CHANGES FROM 2.7 to 2.8

* Make display-panes block the client until a pane is chosen or it
  times out.

* Clear history on RIS like most other terminals do.

* Add an "Any" key to run a command if a key is pressed that is not
  bound in the current key table.

* Expand formats in load-buffer and save-buffer.

* Add a rectangle_toggle format.

* Add set-hook -R to run a hook immediately.

* Add README.ja.

* Add pane focus hooks.

* Allow any punctuation as separator for s/x/y not only /.

* Improve resizing with the mouse (fix resizing the wrong pane in some
  layouts, and allow resizing multiple panes at the same time).

* Allow , and } to be escaped in formats as #, and #}.

* Add KRB5CCNAME to update-environment.

* Change meaning of -c to display-message so the client is used if it
  matches the session given to -t.

* Fixes to : form of SGR.

* Add x and X to choose-tree to kill sessions, windows or panes.

CHANGES FROM 2.6 TO 2.7

* Remove EVENT_* variables from environment on platforms where tmux uses them
  so they do not pass on to panes.

* Fixes for hooks at server exit.

* Remove SGR 10 (was equivalent to SGR 0 but no other terminal seems to do
  this).

* Expand formats in window and session names.

* Add -Z flag to choose-tree, choose-client, choose-buffer to automatically
  zoom the pane when the mode is entered and unzoom when it exits, assuming the
  pane is not already zoomed. This is now part of the default key bindings.

* Add C-g to exit modes with emacs keys.

* Add exit-empty option to exit server if no sessions (defaults to on).

* Show if a filter is present in choose modes.

* Add pipe-pane -I to to connect stdin of the child process.

* Performance improvements for reflow.

* Use RGB terminfo(5) capability to detect RGB colour terminals (the existing
  Tc extension remains unchanged).

* Support for ISO colon-separated SGR sequences.

* Add select-layout -E to spread panes out evenly (bound to E key).

* Support wide characters properly when reflowing.

* Pass PWD to new panes as a hint to shells, as well as calling chdir().

* Performance improvements for the various choose modes.

* Only show first member of session groups in tree mode (-G flag to choose-tree
  to show all).

* Support %else in config files to match %if; from Brad Town in GitHub issue
  1071.

* Fix "kind" terminfo(5) capability to be S-Down not S-Up.

* Add a box around the preview label in tree mode.

* Show exit status and time in the remain-on-exit pane text; from Timo
  Boettcher in GitHub issue 1103.

* Correctly use pane-base-index in tree mode.

* Change the allow-rename option default to off.

* Support for xterm(1) title stack escape sequences (GitHub issue 1075 from
  Brad Town).

* Correctly remove padding cells to fix a UTF-8 display problem (GitHub issue
  1090).

CHANGES FROM 2.5 TO 2.6, 05 October 2017

* Add select-pane -T to set pane title.

* Fix memory leak when lines with BCE are removed from history.

* Fix (again) the "prefer unattached" behaviour of attach-session.

* Reorder how keys are checked to allow keys to be specified that have a
  leading escape. GitHub issue 1048.

* Support REP escape sequence (\033[b).

* Run alert hooks based on options rather than always, and allow further bells
  even if there is an existing bell.

* Add -d flag to display-panes to override display-panes-time.

* Add selection_present format when in copy mode (allows key bindings that do
  something different if there is a selection).

* Add pane_at_left, pane_at_right, pane_at_top and pane_at_bottom formats.

* Make bell, activity and silence alerting more consistent by: removing the
  bell-on-alert option; adding activity-action and silence-action options with
  the same possible values as the existing bell-action; adding a "both" value
  for the visual-bell, visual-activity and visual-silence options to trigger
  both a bell and a message.

* Add a pane_pipe format to show if pipe-pane is active.

* Block signals between forking and resetting signal handlers so that the
  libevent signal handler doesn't get called in the child and incorrectly write
  into the signal pipe that it still shares with the parent. GitHub issue 1001.

* Allow punctuation in pane_current_command.

* Add -c for respawn-pane and respawn-window.

* Wait for any remaining data to flush when a pane is closed while pipe-pane is
  in use.

* Fix working out current client with no target. GitHub issue 995.

* Try to fallback to C.UTF-8 as well as en_US.UTF-8 when looking for a UTF-8
  locale.

* Add user-keys option for user-defined key escape sequences (mapped to User0
  to User999 keys).

* Add pane-set-clipboard hook.

* FAQ file has moved out of repository to online.

* Fix problem with high CPU usage when a client dies unexpectedly. GitHub issue
  941.

* Do a dance on OS X 10.10 and above to return tmux to the user namespace,
  allowing access to the clipboard.

* Do not allow escape sequences which expect a specific terminator (APC, DSC,
  OSC) to wait for forever - use a small timeout. This reduces the chance of
  the pane locking up completely when sent garbage (cat /dev/random or
  similar).

* Support SIGUSR2 to toggle logging on a running server, also generate the
  "out" log file with -vv not -vvvv.

* Make set-clipboard a three state option: on (tmux both sends to outside
  terminal and accepts from applications inside); external (tmux sends outside
  but does not accept inside); and off.

* Fix OSC 4 palette setting for bright foreground colours. GitHub issue 954.

* Use setrgbf and setrgbb terminfo(5) capabilities to set RGB colours, if they
  are available. (Tc is still supported as well.)

* Fix redrawing panes when they are resized several times but end up with the
  size unchanged (for example, splitw/resizep -Z/breakp).

* Major rewrite of choose mode. Now includes preview, sorting, searching and
  tagging; commands that can be executed directly from the mode (for example,
  to delete one or more buffers); and filtering in tree mode.

* choose-window and choose-session are now aliases of choose-tree (in the
  command-alias option).

* Support OSC 10 and OSC 11 to set foreground and background colours.

* Check the U8 capability to determine whether to use UTF-8 line drawing
  characters for ACS.

* Some missing notifications for layout changes.

* Control mode clients now do not affect session sizes until they issue
  refresh-client -C. new-session -x and -y works with control clients even if
  the session is not detached.

* All new sessions that are unattached (whether with -d or started with no
  terminal) are now created with size 80 x 24. Whether the status line is on or
  off does not affect the size of new sessions until they are attached.

* Expand formats in option names and add -F flag to expand them in option values.

* Remember the search string for a pane even if copy mode is exited and entered
  again.

* Some further BCE fixes (scroll up, reverse index).

* Improvements to how terminals are cleared (entirely or partially).

CHANGES FROM 2.4 TO 2.5, 09 May 2017

* Reset updated flag when restarting #() command so that new output is properly
  recognised. GitHub issue 922.

* Fix ECH with a background colour.

* Do not rely on the terminal not moving the cursor after DL or EL.

* Fix send-keys and send-prefix in copy-mode (so C-b C-b works). GitHub issue
  905.

* Set the current pane for rotate-window so it works in command sequences.

* Add pane_mode format.

* Differentiate M-Up from Escape+Up when possible (that is, in terminals with
  xterm(1) style function keys). GitHub issue 907.

* Add session_stack and window_stack_index formats.

* Some new control mode notifications and corresponding hooks:
  pane-mode-changed, window-pane-changed, client-session-changed,
  session-window-changed.

* Format pane_search_string for last search term while in copy mode (useful
  with command-prompt -I).

* Fix a problem with high CPU usage and multiple clients with #(). GitHub issue
  889.

* Fix UTF-8 combining characters in column 0.

* Fix reference counting so that panes are properly destroyed and their
  processes killed.

* Clamp SU (CSI S) parameter to work around a bug in Konsole.

* Tweak line wrapping in full width panes to play more nicely with terminal
  copy and paste.

* Fix when we emit SGR 0 in capture-pane -e.

* Do not change TERM until after config file parsing has finished, so that
  commands run inside the config file can use it to make decisions (typically
  about default-terminal).

* Make the initial client wait until config file parsing has finished to avoid
  racing with commands.

* Fix core when if-shell fails.

* Only use ED to clear screen if the pane is at the bottom.

* Fix multibyte UTF-8 output.

* Code improvements around target (-t) resolution.

* Change how the default target (for commands without -t) is managed across
  command sequences: now it is set up at the start and commands are required
  to update it if needed. Fixes binding command sequences to mouse keys.

* Make if-shell from the config file work correctly.

* Change to always check the root key table if no binding is found in the
  current table (prefix table or copy-mode table or whatever). This means that
  root key bindings will take effect even in copy mode, if not overridden by a
  copy mode key binding.

* Fix so that the history file works again.

* Run config file without a client rather than using the first client, restores
  previous behaviour.

* If a #() command doesn't exit, continue to read from it and use its last full
  line of output.

* Handle slow terminals and fast output better: when the amount of data
  outstanding gets too large, discard output until it is drained and we are
  able to do a full redraw. Prevents tmux sitting on a huge buffer that the
  terminal will take forever to consume.

* Do not redraw a client unless we realistically think it can accept the data -
  defer redraws until the client has nothing else waiting to write.
 
CHANGES FROM 2.3 TO 2.4, 20 April 2017

Incompatible Changes
====================

* Key tables have undergone major changes. Mode key tables are no longer
  separate from the main key tables. All mode key tables have been removed,
  together with the -t flag to bind-key and unbind-key.

  The emacs-edit, vi-edit, emacs-choose and vi-choose tables have been replaced
  by fixed key bindings in the command prompt and choose modes. The mode-keys
  and status-keys options remain.

  The emacs-copy and vi-copy tables have been replaced by the copy-mode and
  copy-mode-vi tables. Commands are sent using the -X and -N flags to
  send-keys. So the following:

    bind -temacs-copy C-Up scroll-up
    bind -temacs-copy -R5 WheelUpPane scroll-up

  Becomes:

    bind -Tcopy-mode C-Up send -X scroll-up
    bind -Tcopy-mode WheelUpPane send -N5 -X scroll-up

  These changes allows the full command parser (including command sequences) and
  command set to be used - for example, the normal command prompt with editing
  and history is now used for searching, jumping, and so on instead of a custom
  one. The default C-r binding is now:

    bind -Tcopy-mode C-r command-prompt -i -p'search up' "send -X search-backward-incremental '%%'"

  There are also some new commmands available with send -X, such as
  copy-pipe-and-cancel.
* set-remain-on-exit has gone -- can be achieved with hooks instead.
* Hooks: before hooks have been removed and only a selection of commands now
  have after hooks (they are no longer automatic). Additional hooks have been
  added.
* The xterm-keys option now defaults to on.

Normal Changes
==============

* Support for mouse double and triple clicks.
* BCE (Background Colour Erase) is now supported.
* All occurrences of a search string in copy mode are now highlighted;
  additionally, the number of search results is displayed. The highlighting
  updates interactively with the default emacs key bindings (incremental
  search).
* source-file now understands glob patterns.
* Formats now have simple comparisons:

    #{==:a,b}
    #{!=:a,b}

* There are the following new formats:

  - #{version} -- the tmux server version;
  - #{client_termtype} -- the terminal type of the client;
  - #{client_name} -- the name of a client;
  - #{client_written} -- the number of bytes written to the client.

* The configuration file now accepts %if/%endif conditional blocks which are
  processed when it is parsed; the argument is a format string (useful with the
  new format comparison options).
* detach-client now has -E to execute a command replacing the client instead of
  exiting.
* Add support for custom command aliases, this is an array option which
  contains items of the form "alias=command". This is consulted when an
  unknown command is parsed.
* break-pane now has -n to specify the new window name.
* OSC 52 support has been added for programs inside tmux to set a tmux buffer.
* The mouse "all event" mode (1003) is now supported.
* Palette setting is now possible (OSC 4 and 104).
* Strikethrough support (a recent terminfo is required).
* Grouped sessions can now be named (new -t).
* terminal-overrides and update-environment are now array options (the previous
  set -ag syntax should work without change).
* There have been substantial performance improvements.

CHANGES FROM 2.2 TO 2.3, 29 September 2016

Incompatible Changes
====================

None.

Normal Changes
==============

* New option 'pane-border-status' to add text in the pane borders.
* Support for hooks on commands: 'after' and 'before' hooks.
* 'source-file' understands '-q' to suppress errors for nonexistent files.
* Lots of UTF8 improvements, especially on MacOS.
* 'window-status-separator' understands #[] expansions.
* 'split-window' understands '-f' for performing a full-width split.
* Allow report count to be specified when using 'bind-key -R'.
* 'set -a' for appending to user options (@foo) is now supported.
* 'display-panes' can now accept a command to run, rather than always
  selecting the pane.

CHANGES FROM 2.1 TO 2.2, 10 April 2016

Incompatible Changes
====================

* The format strings which referenced time have been removed.  Instead:

  #{t:window_activity}

can be used.

* Support for TMPDIR has been removed.  Use TMUX_TMPDIR instead.
* UTF8 detection now happens automatically if the client supports it, hence
  the:

  mouse-utf8
  utf8

  options has been removed.
* The:

  mouse_utf8_flag

  format string has been removed.
* The -I option to show-messages has been removed.  See:

  #{t:start_time}

  format option instead.

Normal Changes
==============

* Panes are unzoomed with selectp -LRUD
* New formats added:

  #{scroll_position}
  #{socket_path}
  #{=10:...} -- limit to N characters (from the start)
  #{=-10:...} -- limit to N characters (from the end)
  #{t:...} -- used to format time-based formats
  #{b:...} -- used to ascertain basename from string
  #{d:...} -- used to ascertain dirname from string
  #{s:...} -- used to perform substitutions on a string

* Job output is run via the format system, so formats work again
* If display-time is set to 0, then the indicators wait for a key to be
  pressed.
* list-keys and list-commands can be run without starting the tmux server.
* kill-session learns -C to clear all alerts in all windows of the session.
* Support for hooks (internal for now), but hooks for the following have been
  implemented:

  alert-bell
  alert-silence
  alert-activity
  client-attached
  client-detached
  client-resized
  pane-died
  pane-exited

* RGB (24bit) colour support.  The 'Tc' flag must be set in the external TERM
  entry (using terminal-overrides or a custom terminfo entry).

CHANGES FROM 2.0 TO 2.1, 18 October 2015

Incompatible Changes
====================

* Mouse-mode has been rewritten.  There's now no longer options for:
	- mouse-resize-pane
	- mouse-select-pane
	- mouse-select-window
	- mode-mouse

  Instead there is just one option:  'mouse' which turns on mouse support
  entirely.
* 'default-terminal' is now a session option.  Furthermore, if this is set
  to 'screen-*' then emulate what screen does.  If italics are wanted, this
  can be set to 'tmux' but this is still new and not necessarily supported
  on all platforms with older ncurses installs.
* The c0-* options for rate-limiting have been removed.  Instead, a backoff
  approach is used.

Normal Changes
==============

* New formats:
	- session_activity
	- window_linked
	- window_activity_format
	- session_alerts
	- session_last_attached
	- client_pid
	- pid
* 'copy-selection', 'append-selection', 'start-named-buffer' now understand
  an '-x' flag to prevent it exiting copying mode.
* 'select-pane' now understands '-P' to set window/pane background colours.
* 'renumber-windows' now understands windows which are unlinked.
* 'bind' now understands multiple key tables.  Allows for key-chaining.
* 'select-layout' understands '-o' to undo the last layout change.
* The environment is updated when switching sessions as well as attaching.
* 'select-pane' now understands '-M' for marking a pane.  This marked pane
  can then be used with commands which understand src-pane specifiers
  automatically.
* If a session/window target is prefixed with '=' then only an exact match
  is considered.
* 'move-window' understands '-a'.
* 'update-environment' understands '-E' when attach-session is used on an
  already attached client.
* 'show-environment' understands '-s' to output Bourne-compatible commands.
* New option: 'history-file' to save/restore command prompt history.
* Copy mode is exited if the history is cleared whilst in copy-mode.
* 'copy-mode' learned '-e' to exit copy-mode when scrolling to end.

CHANGES FROM 1.9a TO 2.0, 06 March 2015

Incompatible Changes
====================

* The choose-list command has been removed.
* 'terminal-overrides' is now a server option, not a session option.
* 'message-limit' is now a server option, not a session option.
* 'monitor-content' option has been removed.
* 'pane_start_path' option has been removed.
* The "info" mechanism which used to (for some commands) provide feedback
  has been removed, and like other commands, they now produce nothing on
  success.

Normal Changes
==============

* tmux can now write an entry to utmp if the library 'utempter' is present
  at compile time.
* set-buffer learned append mode (-a), and a corresponding
  'append-selection' command has been added to copy-mode.
* choose-mode now has the following commands which can be bound:
	- start-of-list
	- end-of-list
	- top-line
	- bottom-line

* choose-buffer now understands UTF-8.
* Pane navigation has changed:
	- The old way of always using the top or left if the choice is ambiguous.
	- The new way of remembering the last used pane is annoying if the
	  layout is balanced and the leftmost is obvious to the user (because
	  clearly if we go right from the top-left in a tiled set of four we want
	  to end up in top-right, even if we were last using the bottom-right).

      So instead, use a combination of both: if there is only one possible
      pane alongside the current pane, move to it, otherwise choose the most
      recently used of the choice.
* 'set-buffer' can now be told to give names to buffers.
* The 'new-session', 'new-window', 'split-window', and 'respawn-pane' commands
  now understand multiple arguments and handle quoting problems correctly.
* 'capture-pane' understands '-S-' to mean the start of the pane, and '-E-' to
  mean the end of the pane.
* Support for function keys beyond F12 has changed.  The following explains:
	- F13-F24 are S-F1 to S-F12
	- F25-F36 are C-F1 to C-F12
	- F37-F48 are C-S-F1 to C-S-F12
	- F49-F60 are M-F1 to M-F12
	- F61-F63 are M-S-F1 to M-S-F3

 Therefore, F13 becomes a binding of S-F1, etc.
* Support using pane id as part of session or window specifier (so % means
  session-of-%1 or window-of-%1) and window id as part of session
  (so @1 means session-of-@1).
* 'copy-pipe' command now understands formats via -F
* 'if-shell'  command now understands formats via -F
* 'split-window' and 'join-window' understand -b to create the pane to the left
  or above the target pane.

CHANGES FROM 1.9 TO 1.9a, 22 February 2014

NOTE: This is a bug-fix release to address some important bugs which just
missed the 1.9 deadline, but were found afterwards.

Normal Changes
==============

* Fix crash due to uninitialized lastwp member of layout_cell
* Fix -fg/-bg/-style with 256 colour terminals.  

CHANGES FROM 1.8 TO 1.9, 20 February 2014

NOTE:  This release has bumped the tmux protocol version.  It is therefore
advised that the prior tmux server is restarted when this version of tmux is
installed, to avoid protocol mismatch errors for newer clients trying to
talk to an older running tmux server.

Incompatible Changes
====================

* 88 colour support has been removed.
* 'default-path' has been removed.  The new-window command accepts '-c' to
  cater for this.  The previous value of "." can be replaced with: 'neww -c
  $PWD', the previous value of '' which meant current path of the pane can
  be specified as:  'neww -c "#{pane_current_path}"'

Deprecated Changes
==================

* The single format specifiers:  #A -> #Z (where defined) have been
  deprecated and replaced with longer-named equivalents, as listed in the
  FORMATS section of the tmux manpage.
* The various foo-{fg,bg,attr} commands have been deprecated and replaced
  with equivalent foo-style option instead.  Currently this is still
  backwards-compatible, but will be removed over time.

Normal Changes
==============

* A new environment variable TMUX_TMPDIR is now honoured, allowing the
  socket directory to be set outside of TMPDIR (/tmp/ if not set).
* If -s not given to swap-pane the current pane is assumed.
* A #{pane_synchronized} format specifier has been added to be a conditional
  format if a pane is in a synchronised mode (c.f. synchronize-panes)
* Tmux now runs under Cygwin natively.
* Formats can now be nested within each other and expanded accordingly.
* Added 'automatic-rename-format' option to allow the automatic rename
  mechanism to use something other than the default of
  #{pane_current_command}.
* new-session learnt '-c' to specify the starting directory for that session
  and all subsequent windows therein.
* The session name is now shown in the message printed to the terminal when
  a session is detached.
* Lots more format specifiers have been added.
* Server race conditions have been fixed; in particular commands are not run
  until after the configuration file is read completely.
* Case insensitive searching in tmux's copy-mode is now possible.
* attach-session and switch-client learnt the '-t' option to accept a window
  and/or a pane to use.
* Copy-mode is only exited if no selection is in progress.
* Paste key in copy-mode is now possible to enter text from the clipboard.
* status-interval set to '0' now works as intended.
* tmux now supports 256 colours running under fbterm.
* Many bug fixes!

CHANGES FROM 1.7 TO 1.8, 26 March 2013

Incompatible Changes
====================

* layout redo/undo has been removed.

Normal Changes
==============

* Add halfpage up/down bindings to copy mode.
* Session choosing fixed to work with unattached sessions.
* New window options window-status-last-{attr,bg,fg} to denote the last
  window which was active.
* Scrolling in copy-mode now scrolls the region without moving the mouse
  cursor.
* run-shell learnt '-t' to specify the pane to use when displaying output.
* Support for middle-click pasting.
* choose-tree learns '-u' to start uncollapsed.
* select-window learnt '-T' to toggle to the last window if it's already
  current.
* New session option 'assume-paste-time' for pasting text versus key-binding
  actions.
* choose-* commands now work outside of an attached client.
* Aliases are now shown for list-commands command.
* Status learns about formats.
* Free-form options can be set with set-option if prepended with an '@'
  sign.
* capture-pane learnt '-p' to send to stdout, and '-e' for capturing escape
  sequences, and '-a' to capture the alternate screen, and '-P' to dump
  pending output.
* Many new formats added (client_session, client_last_session, etc.)
* Control mode, which is a way for a client to send tmux commands.
  Currently more useful to users of iterm2.
* resize-pane learnt '-x' and '-y' for absolute pane sizing.
* Config file loading now reports errors from all files which are loaded via
  the 'source-file' command.
* 'copy-pipe' mode command to copy selection and pipe the selection to a
  command.
* Panes can now emit focus notifications for certain applications
  which use those.
* run-shell and if-shell now accept formats.
* resize-pane learnt '-Z' for zooming a pane temporarily.
* new-session learnt '-A' to make it behave like attach-session.
* set-option learnt '-o' to prevent setting an option which is already set.
* capture-pane and show-options learns '-q' to silence errors.
* New command 'wait-for' which blocks a client until woken up again.
* Resizing panes will now reflow the text inside them.
* Lots and lots of bug fixes, fixing memory-leaks, etc.
* Various manpage improvements.

CHANGES FROM 1.6 TO 1.7, 13 October 2012

* tmux configuration files now support line-continuation with a "\" at the
  end of a line.
* New option status-position to move the status line to the top or bottom of
  the screen.
* Enforce history-limit option when clearing the screen.
* Give each window a unique id, like panes but prefixed with @.
* Add pane id to each pane in layout description (while still accepting
  the old form).
* Provide defined ways to set the various default-path possibilities: ~
  for home directory, . for server start directory, - for session start
  directory and empty for the pane's working directory (the default). All
  can also be used as part of a relative path (eg -/foo). Also provide -c
  flags to neww and splitw to override default-path setting.
* Add -l flag to send-keys to send input literally (without translating
  key names).
* Allow a single option to be specified to show-options to show just that
  option.
* New command "move-pane" (like join-pane but allows the same window).
* join-pane and move-pane commands learn "-b" option to place the pane to
  the left or above.
* Support for bracketed-paste mode.
* Allow send-keys command to accept hex values.
* Add locking around "start-server" to avoid race-conditions.
* break-pane learns -P/-F arguments for display formatting.
* set-option learns "-q" to make it quiet, and not print out anything.
* copy mode learns "wrap-search" option.
* Add a simple form of output rate limiting by counting the number of
  certain C0 sequences (linefeeds, backspaces, carriage returns) and if it
  exceeds a threshold (current default 250/millisecond), start to redraw
  the pane every 100 milliseconds instead of making each change as it
  comes. Two configuration options - c0-change-trigger and
  c0-change-interval.
* find-window learns new flags:  "-C", "-N", "-T" to match against either or
  all of a window's content, name, or title.  Defaults to all three options
  if none specified.
* find-window automatically selects the appropriate pane for the found
  matches.
* show-environment can now accept one option to show that environment value.
* Exit mouse mode when end-of-screen reached when scrolling with the mouse
  wheel.
* select-layout learns -u and -U for layout history stacks.
* kill-window, detach-client, kill-session all  learn "-a" option for
  killing all but the current thing specified.
* move-window learns "-r" option to renumber window sequentially in a
  session.
* New session option "renumber-windows" to automatically renumber windows in
  a session when a window is closed.  (see "move-window -r").
* Only enter copy-mode on scroll up.
* choose-* and list-* commands all use "-F" for format specifiers.
* When spawning external commands, the value from the "default-shell" option
  is now used, rather than assuming /bin/sh.
* New choose-tree command to render window/sessions as a tree for selection.
* display-message learns new format options.
* For linked-windows across sessions, all flags for that window are now
  cleared across sessions.
* Lots and lots of bug fixes, fixing memory-leaks, etc.
* Various manpage improvements.

CHANGES FROM 1.5 TO 1.6, 23 January 2012

* Extend the mode-mouse option to add a third choice which means the mouse
  does not enter copy mode.
* Add a -r flag to switch-client to toggle the client read-only flag.
* Add pane-base-index option.
* Support \ for line continuation in the configuration file.
* Framework for more powerful formatting of command output and use it for
  list-{panes,windows,sessions}. This allows more descriptive replacements
  (such as #{session_name}) and conditionals.
* Mark dead panes with some text saying they are dead.
* Reject $SHELL if it is not a full path.
* Add -S option to refresh-client to redraw status line.
* Add an else clause for if-shell.
* Try to resolve relative paths for loadb and saveb (first, using client
  working directory, if any, then default-path or session working directory).
* Support for \e[3J to clear the history and send the corresponding
  terminfo code (E3) before locking.
* When in copy mode, make repeat count indicate buffer to replace, if used.
* Add screen*:XT to terminal-overrides for tmux-in-tmux.
* Status-line message attributes added.
* Move word-separators to be a session rather than window option.
* Change the way the working directory for new processes is discovered. If
  default-path isn't empty, it is used. Otherwise, if a new window is created
  from the command-line, the working directory of the client is used. If not,
  platform specific code is used to retrieve the current working directory
  of the process in the active pane. If that fails, the directory where the
  session was created is used, instead.
* Do not change the current pane if both mouse-select-{pane,window} are
  enabled.
* Add \033[s and \033[u to save and restore cursor position.
* Allow $HOME to be used as default-path.
* Add CNL and CPL escape sequences.
* Calculate last position correctly for UTF-8 wide characters.
* Add an option allow-rename to disable the window rename escape sequence.
* Attributes for each type of status-line alert (ie bell, content and
  activity) added. Therefore, remove the superfluous options
  window-status-alert-{attr,bg,fg}.
* Add a -R flag to send-keys to reset the terminal.
* Add strings to allow the aixterm bright colours to be used when
  configuring colours.
* Drop the ability to have a list of keys in the prefix in favour of two
  separate options, prefix and prefix2.
* Flag -2 added to send-prefix to send the secondary prefix key.
* Show pane size in top right of display panes mode.
* Some memory leaks plugged.
* More command-prompt editing improvements.
* Various manpage improvements.
* More Vi mode improvements.

CHANGES FROM 1.4 TO 1.5, 09 July 2011

* Support xterm mouse modes 1002 and 1003.
* Change from a per-session stack of buffers to one global stack. This renders
  copy-buffer useless and makes buffer-limit now a server option.
* Fix most-recently-used choice by avoiding reset the activity timer for
  unattached sessions every second.
* Add a -P option to new-window and split-window to print the new window or
  pane index in target form (useful to pass it into other commands).
* Handle a # at the end of a replacement string (such as status-left)
  correctly.
* Support for UTF-8 mouse input (\033[1005h) which was added in xterm 262.
  If the new mouse-utf8 option is on, UTF-8 mouse input is enabled for all
  UTF-8 terminals. The option defaults to on if LANG etc are set in the same
  manner as the utf8 option.
* Support for HP-UX.
* Accept colours of the hex form #ffffff and translate to the nearest from the
  xterm(1) 256-colour set.
* Clear the non-blocking IO flag (O_NONBLOCK) on the stdio file descriptors
  before closing them (fixes things like "tmux ls && cat").
* Use TMPDIR if set.
* Fix next and previous session functions to actually work.
* Support -x and -y for new-session to specify the initial size of the window
  if created detached with -d.
* Make bind-key accept characters with the top-bit-set and print them as octal.
* Set $TMUX without the session when background jobs are run.
* Simplify the way jobs work and drop the persist type, so all jobs are
  fire-and-forget.
* Accept tcgetattr/tcsetattr(3) failure, fixes problems with fatal() if the
  terminal disappears while locked.
* Add a -P option to detach to HUP the client's parent process (usually causing
  it to exit as well).
* Support passing through escape sequences to the underlying terminal by using
  DCS with a "tmux;" prefix.
* Prevent tiled producing a corrupt layout when only one column is needed.
* Give each pane created in a tmux server a unique id (starting from 0), put it
  in the TMUX_PANE environment variable and accept it as a target.
* Allow a start and end line to be specified for capture-pane which may be
  negative to capture part of the history.
* Add -a and -s options to lsp to list all panes in the server or session
  respectively. Likewise add -s to lsw.
* Change -t on display-message to be target-pane for the #[A-Z] replacements
  and add -c as target-client.
* The attach-session command now prefers the most recently used unattached
  session.
* Add -s option to detach-client to detach all clients attached to a session.
* Add -t to list-clients.
* Change window with mouse wheel over status line if mouse-select-window is on.
* When mode-mouse is on, automatically enter copy mode when the mouse is
  dragged or the mouse wheel is used. Also exit copy mode when the mouse wheel
  is scrolled off the bottom.
* Provide #h character pair for short hostname (no domain).
* Don't use strnvis(3) for the title as it breaks UTF-8.
* Use the tsl and fsl terminfo(5) capabilities to update terminal title and
  automatically fill them in on terminals with the XT capability (which means
  their title setting is xterm-compatible).
* Add a new option, mouse-resize-pane. When on, panes may be resized by
  dragging their borders.
* Fix crash by resetting last pane on {break,swap}-pane across windows.
* Add three new copy-mode commands - select-line, copy-line, copy-end-of-line.
* Support setting the xterm clipboard when copying from copy mode using the
  xterm escape sequence for the purpose (if xterm is configured to allow it).
* Support xterm(1) cursor colour change sequences through terminfo(5) Cc
  (set) and Cr (reset) extensions.
* Support DECSCUSR sequence to set the cursor style with two new terminfo(5)
  extensions, Cs and Csr.
* Make the command-prompt custom prompts recognize the status-left option
  character pairs.
* Add a respawn-pane command.
* Add a couple of extra xterm-style keys that gnome terminal provides.
* Allow the initial context on prompts to be set with the new -I option to
  command-prompt. Include the current window and session name in the prompt
  when renaming and add a new key binding ($) for rename session.
* Option bell-on-alert added to trigger the terminal bell when there is an
  alert.
* Change the list-keys format so that it shows the keys using actual tmux
  commands which should be able to be directly copied into the config file.
* Show full targets for lsp/lsw -a.
* Make confirm-before prompt customizable with -p option like command-prompt
  and add the character pairs #W and #P to the default kill-{pane,window}
  prompts.
* Avoid sending data to suspended/locked clients.
* Small memory leaks in error paths plugged.
* Vi mode improvements.

CHANGES FROM 1.3 TO 1.4, 27 December 2010

* Window bell reporting fixed.
* Show which pane is active in the list-panes output.
* Backoff reworked.
* Prevent the server from dying when switching into copy mode when already
  in a different mode.
* Reset running jobs when the status line is enabled or disabled.
* Simplify xterm modifier detection.
* Avoid crashing in copy mode if the screen size is too small for the
  indicator.
* Flags -n and -p added to switch-client.
* Use UTF-8 line drawing characters on UTF-8 terminals, thus fixing some
  terminals (eg putty) which disable the vt100 ACS mode switching sequences
  in UTF-8 mode. On terminals without ACS, use ASCII equivalents.
* New server option exit-unattached added.
* New session option destroy-unattached added.
* Fall back on normal session choice method if $TMUX exists but is invalid
  rather than rejecting.
* Mark repeating keys with "(repeat)" in the key list.
* When removing a pane, don't change the active pane unless the active pane
  is actually the one being removed.
* New command last-pane added.
* AIX fixes.
* Flag -a added to unbind-key.
* Add XAUTHORITY to update-environment.
* More info regarding window and pane flags is now shown in list-*.
* If VISUAL or EDITOR contains "vi" configure mode-keys and status-key to vi.
* New window option monitor-silence and session option visual-silence added.
* In the built-in layouts distribute the panes more evenly.
* Set the default value of main-pane-width to 80 instead of 81.
* Command-line flag -V added.
* Instead of keeping a per-client prompt history make it global.
* Fix rectangle copy to behave like emacs (the cursor is not part of the
  selection on the right edge but on the left it is).
* Flag -l added to switch-client.
* Retrieve environment variables from the global environment rather than
  getenv(3), thus allowing them to be updated during the configuration file.
* New window options other-pane-{height,width} added.
* More minor bugs fixed and manpage improvements.

CHANGES FROM 1.2 TO 1.3, 18 July 2010

* New input parser.
* Flags to move through panes -UDLR added to select-pane.
* Commands up-pane, and down-pane removed, since equivalent behaviour is now
  available through the target flag (-t:+ and -t:-).
* Jump-forward/backward in copy move (based on vi's F, and f commands).
* Make paste-buffer accept a pane as a target.
* Flag -a added to new-window to insert a window after an existing one, moving
  windows up if necessary.
* Merge more mode into copy mode.
* Run job commands explicitly in the global environment (which can be modified
  with setenv -g), rather than with the environment tmux started with.
* Use the machine's hostname as the default title, instead of an empty string.
* Prevent double free if the window option remain-on-exit is set. 
* Key string conversions rewritten.
* Mark zombie windows as dead in the choose-window list.
* Tiled layout added.
* Signal handling reworked.
* Reset SIGCHLD after fork to fix problems with some shells.
* Select-prompt command removed. Therefore, bound ' to command-prompt -p index
  "select-window -t:%%" by default.
* Catch SIGHUP and terminate if running as a client, thus avoiding clients from
  being left hanging around when, for instance, a SSH session is disconnected.
* Solaris 9 fixes (such as adding compat {get,set}env(3) code).
* Accept none instead of default for attributes.
* Window options window-status-alert-{alert,bg,fg} added.
* Flag -s added to the paste-buffer command to specify a custom separator.
* Allow dragging to make a selection in copy mode if the mode-mouse option is
  set.
* Support the mouse scroll wheel.
* Make pipe-pane accept special character sequences (eg #I).
* Fix problems with window sizing when starting tmux from .xinitrc.
* Give tmux sockets (but not the containing folder) group permissions.
* Extend the target flags (ie -t) to accept an offset (for example -t:+2), and
  make it wrap windows, and panes.
* New command choose-buffer added.
* New server option detach-on-destroy to set what happens to a client when the
  session it is attached to is destroyed. If on (default), the client is
  detached. Otherwise, the client is switched to the most recently active of
  the remaining sessions.
* The commands load-buffer, and save-buffer now accept a dash (-) as the file
  to read from stdin, or write to stdout.
* Custom layouts added.
* Additional code reduction, bug fixes, and manpage enhancements.

CHANGES FROM 1.1 TO 1.2, 10 March 2010

* Switch to libevent.
* Emulate the ri (reverse index) capability, ergo allowing tmux to at least
  start on Sun consoles (TERM=sun, or sun-color).
* Assign each entry a number, or lowercase letter in choose mode, and accept
  that as a shortcut key.
* Permit top-bit-set characters to be entered in the status line.
* Mark no-prefix keys with (no prefix), rather than [] in list-keys.
* New command show-messages (alias showmsgs), and new session option
  message-limit, to show a per-client log of status lines messages up to the
  number defined by message-limit.
* Do not interpret #() for display-message to avoid leaking commands.
* New window options window-status-format, and window-status-current-format to
  control the format of each window in the status line.
* Add a -p flag to display-message to print the output, instead of displaying
  it in the status line.
* Emulate il1, dl1, ich1 to run with vt100 feature set.
* New command capture-pane (alias capturep) to copy the entire pane contents
  to a paste buffer.
* Avoid duplicating code by adding a -w flag to set-option, and show-options to
  set, and show window options. The commands set-window-option, and
  show-window-options are now aliases.
* Panes can now be referred to as top, bottom, top-left, etc.
* Add server-wide options, which can be set with set-option -s, and shown with
  show-options -s.
* New server option quiet (like -q from the command line).
* New server option escape-time to set the timeout used to detect if escapes
  are alone, part of a function key, or meta sequence.
* New session options pane-active-border-bg, pane-active-border-fg,
  pane-border-bg, and pane-border-fg to set pane colours.
