I keep my home directory in git, a distributed version control system. There is a wiki about keeping your home directory in a version control system aka vcs-home. There is also a mailing list for vcs-home. At some point I will get around to writing up some of my vcs-home experiences for the wiki.
Free/Open Source software for Windows
Here is a diagram of the linux audio stack I made:
Kivio diagram:
realistic linux audio
v2.flw
PNG: 
I also made some diagrams of public key encryption and decryption:
PNG: 
Inkscape SVG:
public key
cryptography pgp encryption.svg
public key
cryptography pgp decryption.svg
Original Visio:
public key cryptography
pgp.vsd
I welcome any suggestions or corrections, and I hereby place these diagrams and images these under the Creative Commons Attribution 3.0 licence.