PRAGMA Advanced Document Engineering
Free TEX distributions
http://www.tug.org/texlive
TEXLIVE
Karl Berry, Norbert Preining & team
http://www.fsci.fuk.kindai.ac.jp/kakuto/win32-ptex
WTEX - mswindows
Akira Kakuto
http://www.miktex.org
MIKTEX - mswindows
C. Schenk