There's loads of freeware available that's useful, but here's my shortlist of the genuine must-have Apple software, from an I-was-a-Linux-weenie point of view:
- MacVim - The best port of (the best text editor) Vim to the Mac.
- NeoOffice - Very good native port of OpenOffice, the multi-platform Microsoft Office replacement. OpenOffice will soon have a native Mac release, but until then this is great.
- Adium - A multi-protocol instant messenger
- Transmission - Sweet little torrent client
- Audacity - Simple but capable audio editor
- MacFUSE (and MacFusion) - Native filesystems for many protocols (ssh, NTFS, and many many more). MacFusion is a cute menubar GUI to make using MacFUSE more convenient.
- The Unarchiver - Better than the built-in file decompression utility. Simple and unobtrusive.
- The Gimp - The well-known image processing package. Sadly, runs under X11 - not a native app.
- MacSword - An awesome interface to the Sword bible study package.
- iRed Lite - Allows you to use the Apple remote to do all sorts of useful things (I've used it as a remote presentation controller)
Plugins and utilities:
- Growl - Notification system for MacOS. Many applications support growl notifications.
- Afloat - Useful program that allows most application's windows to be pinned to the top of the window stack. Watch a quicktime movie easily whilst working on a document!
- Inquistor - Awesome Safari search plugin. Calls itself "Spotlight for the web". I can't argue with that,
- MenuMeters - System profile utility that puts info up in the menu bars. Very useful to see how much CPU Cubase is eating up!
- OpenTerminalHere - Great Finder plugin that opens a terminal window with the working directory set to the current finder path.
- Parallels - The infamous utility that lets you run Windows at the same time as Mac OS. It is truly awesome.
- Cubase - Well, to be fair, there's a ton of muso application's I'd recommend, like the incredible TruePianos and many, many more.
Before leopard, there were other packages that were important to me: