Fedora Electronic Lab
The Fedora Project have released a number of "custom spins". These are LiveCD's of Fedora 8 with packages oriented toward a particular interest.
If you have installed Werewolf already, then these custom spins aren't especially interesting. All the packages can be installed with yum. But there are a lot of Windows folks out there struggling with the limited versions of various PCB and schematic programs, or trying to make do with a general purpose CAD program to do electronics work.
Well, the Fedora Electronics Lab solves that problem. Although touted as a tool for the VLSI designer, FEL includes all the stuff the electronics hobbyist would like.
With the integrated gEDA suite, the designer can draw the schematic, and the netlist can be generated from the schematic. The circuit can then be simulated with SPICE. When the circuit is "soup", the PCB can be layed out. Gerbers can be generated from the PCB layout, as well as viewed.
In addition, the gputils set of PIC tools is included for developing the code, including the gpsim simulator, as well as a number of GUI tools for working out your PIC logic. There are also AVR tools. In addition, the Small Device C Compiler is included for those that don't like to grok assembler.
Perhaps the coolest thing for the Windows-based ham; you don't need to install anything. Simply burn the ISO onto a CD and boot the CD.
http://fedoraproject.org/wiki/Features/FedoraElectronicLab