Where to get:

The core TEX system with few style files and fonts is (for Unix systems) available via anonymous FTP from ftp://ftp.tug.org/tex/. There are also complete packages available with more fonts and styles:

• teTeX is for Unix-systems, it's available from
  ftp://ftp.dante.de/pub/tex/systems/unix/teTeX
• emTeX is for PC-based systems, available from
  ftp://ftp.dante.de/pub/tex/systems/msdos/emtex