For studying the differences between prior tmux versions to check compatibility with legacy versions.

Get source:

$ git clone git://git.code.sf.net/p/tmux/tmux-code tmux-tmux-code tmux
$ cd tmux

Converted with:

$ git checkout <version>
$ ./configure
$ make
$ groff -t -e -mandoc -Tascii tmux.1 | col -bx > manpage.txt

repeat for versions.

Create a git-diff style diff of version manuals:

$ diff -u 1.6 1.8 > 1_6__1_8.diff