On www.emacswiki.org, there's this fact mentioned:
The [emacs lisp] manual has license GFDL and thus the DFSG (Debian Free Software Guidelines) don't consider it free.
Ain't it bizarre? FSF's GNU Emacs, the mothership of all Free Software, and Debian Linux, the mothership of hacker linux, originally with support of Richard Stallman, have come to this quarrel.
Such quarrel are quite severe and wide-spread among open source communities. BSD's antagonistic forks, GNU vs MIT/BSD/Unices, Emacs vs XEmacs, Free Software vs Open Source, the KDE vs Gnome, GNU vs Linux, Firefox logo vs Debian, the rise and fall and rise and fall of Java as “free” (aka the Java Trap), OpenOffice vs LibreOffice, Richard Stallman vs Linus Torvalds, Richard Stallman vs Eric Raymond, Richard Stallman vs everybody else, …
These tech geekers are supposed to be the ethics gods of humanity, peace, freedom, et al, in reality, they are just scumbags like most human animals on earth, when YOUR self-interest is involved.