Apache - Apache Software Foundation Distribution Directory.

CPAN - Comprehensive Perl Archive Network.

Crux - Lightweight Linux distribution for the x86-64 architecture targeted at experienced Linux users.

CTAN - Comprehensive TeX Archive Network.

Cygwin - a large collection of GNU and Open Source tools which provide functionality similar to a Linux distribution on Windows.

GNU - GNU is an operating system that is free software—that is, it respects users' freedom.

Htdig - WWW Search Engine Software.

Knoppix - a bootable Live system on CD, DVD or USB flash drives, consisting of a representative collection of GNU/Linux software.

LDP - The Linux Documentation Project.

PuTTY - a free implementation of Telnet and SSH for Windows and Unix platforms.

Vim - a professional text editor. It can be used to edit plain text in a highly productive way.

X - a open source implementation of the X Window System.