wikiCalc is a unique tool that offers a combination of spreadsheet functionality and wiki features. This may sound like a strange pairing, but wikiCalc provides a refreshingly new approach to the spreadsheet concept.
Hardware manufacturer HP has released the source code for its Advanced File System (AdvFS), which it uses for the Tru64 Unix OS under the GPL, along with a Linux reference implementation.
The Facebook social network has released part of its source code under the "Facebook Open Platform" label, including the F8 developer platform which was released one year ago.