Neat Software
Windows
LiteStep
Alternate shell for Windows. Much prettier, and some themes are indeed also more functional. I’ve grown accustomed to it. I fear, however, that it is becoming abandonware, so there is an installer here Δ.
Froost
I tried to use this to make a few things (namely foobar2000 0.9+) transparent always. It pretty much sucks though. Looking for a replacement. graaag!
Windows also has its own section for software that’s around to fix annoyances.
Net stuff
Mozilla Sunbird
I love my Mac and iCal, but I’ll be damned if it isn’t a pain in the ass to have only one calendar that doesn’t synchronize. oh wait, what, mozilla sunbird reads .ics files? .ics is its native format? that is awesome. Sadly, however, iCal is a bitch and loves to clobber the files on the DAV share, and doesn’t have any way to do real sharing- just publishing.
Mozilla Firefox
Mentioned here mostly so I can remind myself to always turn on network.http.pipelining in the about:config page, as well as holding an adblock filter list. Also, do not forget to install greasemonkey and greasemonkey user scripts.
LiteStep
A very wonderful shell replacement for Windows. Makes me not mind using Windows at all anymore! Development, however, is very on/off, and it seems to be mostly stagnant since 2003..
Notepad++
A relatively lightweight application that allows me to eliminate the crappy Notepad/Wordpad combo that comes with windows. (Fast opening? Notepad. Unix/Mac linefeeds? Wordpad.)
XChat (free build)
The XChat folk decided that the version that they compiled for Windows would be a pay version, because it was “too difficult to compile”. Someone else got pissed about this and decided it wasn’t too difficult after all, and compiled their own version.
Media stuff
Foobar2000
A real man’s man’s audio player. Very powerful tagging features and simple (but extensible) user interface. The new beta (0.9) is much, much better about not blocking operations during file writes, but damn, it’s been without an SDK forever, and the current installer is missing an awful lot of components.
Soulseek
Only decent ⚠ P2P these days.
AutoDVRConvert
Strips the mpeg-2 stream out of ms-dvr files for further transcoding. yay!
mp3directcut
Clip bits from mp3s directly, no reencoding.
musikCube
A new audio player with a purely functional aesthetic. Includes sqlite for music library functions. Speedy searching and unobtrusive db↔filesystem sync done in the background at startup (very cool). Still missing some crucial features, but very promising.
MusicBrainz
Tagging software with a really dumb name. Uses audio fingerprinting to identify songs and tag them according to information inside of its collaboratively-edited database of music metadata.
Electricsheep
Distributed-rendering animated fractal flames (class of IFS fractals studied/implemented by Scott Draves). Simply the best screensaver ever, but a bit too easy to stare at for hours.
Irfanview
Best free image browser for Windows.
DOSBox
DOS emulator.
Other Stuff
Bitmap Font Writer
This allows you to type things out from bitmapped fonts. yay! used this to get the River City Ransom font (png) on my home page.
Synergy
Allows you to use one kbd/mouse to control multiple systems. This doesn’t sound all that great, but this works across operating systems, and furthermore keeps the clipboard synced.
Mac
SMAC Carbon
also kept here in case that other spot goes away.
SubEthaEdit
Collaborative text editing software that works very well (and with syntax highlighting, too! I still prefer vim on features alone, but the collaborative edit feature is very, very nice. Too bad it’s not open software. Jerks.
Adium
The best IM client, bar none.
MacIrssi
Mac port of irssi. Main site seems down all the time so here’s a post of the latest leopard working version.
shine2.se font

Vox
little music player for osx. lighter than itunes, without library management. keeps me from adding everything i double click on to the “library”
Lunix
mt-daapd
Very excellent DAAP share daemon. Apparently, according to its wiki, it has the ability to transcode FLAC on the fly. That’d be awesome. I don’t have that part going yet.
mjs
console-based linux jukebox. bet i could get this going with a netboot image on one of those wee biscuit pcs. (and i did)
swfdec
hey, finally, a flash plugin that runs on amd64! suck it macromedia.
jack
oh hot crap if this isn’t the goddamn coolest thing ever. arts now supports output to jack, so all KDE apps can use sond with jack running now.
websec
monitor webpages and have diffs sent to you when they change.