Software

Browsers

• K-Meleon (browser based on Mozilla)
• Mozilla Firebird

Music and sound

• WinAmp
• Ogg Vorbis
• Monkey's Audio A fast and powerful lossless audio compressor
• WinAmp MIDI to WAV conversion

Editors and IDEs

• GNU Emacs
• vim
• ned "Text editor of the future"; contains a number of interesting links to texts about other editors
• Bram Moolenaar: Seven habits of effective text editing
• Eclipse intro

Upgrades and patches

• Windows 2000 Service Pack 1

Tools and stuff

• VDMSound: VDMSound provides sound support to DOS boxes under Windows NT 4.0 and Windows 2000

Command shells

• Working more productively with bash 4.x
• 4DOS/4NT

Other

• Nullsoft's WASTE (mirror) (more mirrors)
• OldVersion get older version of popular software. "because newer is not always better"
• Inno Setup

• Google software principles