The TEX Live Guide for TeX Live 2012 has in section 9 “Release history” following information about the present version (page 39):
tlmgr supports updates from multiple network repositories. The section
on multiple repositories in the
tlmgr help output has more.
\XeTeXdashbreakstate is set to
1 by default, for both
xelatex. This allows line breaks after em-dashes and
en-dashes, which has always been the behavior of plain TeX, LaTeX,
LuaTeX, etc. Existing XeTeX documents which must retain perfect
line-break compatibility will need to set
The output files generated by
dvips, among others, can now
The 35 standard PostScript fonts are included in the output of
by default, since so many different versions of them are extant.
In the restricted
\write18 execution mode, set by default,
now an allowed program.
texmf.cnf file is also found in
/usr/local/texlive/texmf-local/web2c/texmf.cnf, if it exists.
updmap script reads a per-tree
updmap.cfg instead of one global
config. This change should be invisible, unless you edited your
updmap.cfg's directly. The
updmap help output has more.
Platforms: armel-linux and mipsel-linux added; sparc-linux and
i386-netbsd are no longer in the main distribution, but are available
for installation as custom binaries, along with a variety of other
"Known issues in TeX Live 2012" adds:
We forgot to mention a notable change in TL 2012: the Japanese uptex
engine (Unicode-enhanced ptex) and related programs (uplatex,
upbibtex, etc.) are now included.