free software for MS Windows

I generally avoid MS Windows though I occasionally investigate software for it, and accumulate the results here. If you think this list should be modified, please send suggestions to: help!

Ideally, these programs should be:

Beware that some installers install unwanted software (e.g. browser toolbars) by default; just disable those options when running the installer.

Software is open source unless marked* (with an asterisk).

utilities

Sumatra PDF
PDF viewer & browser plugin; small/fast alternative to Adobe Reader
PDFCreator | qvPDF
PDF virtual printer; PDF output from any program that can print
IrfanView* | XnView*
image viewer
7-Zip
archive utility; supports many formats including zip
FreeFileSync
backup; fast folder comparison/synchronization
SequoiaView* | WinDirStat
disk usage visualisation utilizing treemaps

UWIN
Unix environment; build and run Unix tools (alternative to Cygwin)
GnuWin
GNU tools; individual native Win32 ports
Code Browser
text editor; fast/functional/clean (supports folding and elastic tabstops)
PSPad
text editor; regex, syntax, hex editor, diff, macros, …
AutoHotKey
automation; macro-creation, &c.; also does text expansion from abbreviations
FARR (Find and Run Robot)*
keyboard control; comprehensive launcher, &c.

network

Firefox
web browser with ad blocker, script control, and other extensions
Thunderbird
e-mail client; easily imports settings from Outlook and Outlook Express
qBittorrent
BitTorrent client
Miranda
instant messenging client; supports many services/protocols

HTTtrack
website mirror; a welcome alternative to wget
PuTTY
SSH client
WinSCP
FTP/SFTP/SCP client
TightVNC | RealVNC
VNC client & server

audio/video

VLC
media player; plays most audio/video formats
Foobar2000* | XMPlay*
audio player
Exact Audio Copy*
CD ripper
ImgBurn* | CDBurnerXP*
CD/DVD writer

security, &c.

Microsoft Security Essentials*
anti-virus; this actually works well (believe it or not, but it requires WGA)
Avira AntiVir Personal*
anti-virus; alternative to MSE (see: AV-Comparatives, Virus Bulletin)
PeerBlock
blocks connections to a specific list IP addresses
Hiren’s Boot CD*
boot CD with many utilities

unfiled

LibreOffice
office applications; alternative to MS Office

software directories/reviews

TinyApps.Org
software directory of very small/fast/efficient programs (mostly free)
Portable Freeware
software directory and reviews
Gizmos Freeware Reviews
software reviews