Parsimonious XML is an interesting approach to making XML more readable.
Cobian backup is a cool Windows backup program by Luis Cobian.
Eric Hellweg wrote a fascinating profile of Waste p2p chat by Justin Frankel who resigned amidst scandal from Nullsoft. According to reports, Justin wrote Justin when he was about 18 and did gnutella a few years later. What Justin did was wrong from a legal standpoint, but it shows the conflict that exists between the anarchic share-the-code mentality that exists in open source and corporate attempts to share this impulse.