LibCMT (Composable Memory Transactions Library) implements a transactional model of concurrency, where deadlock is not possible and transactions are composable (small transactions can be glued together to form larger transactions without extra effort). It is written as a Glib extension but can be used with any thread library, not just GThread.
iBookshelf is an application for cataloging your book collection and designing bookshelves based on this data. It supports ISBN entry using a CueCat, a standard barcode scanner, or manual entry. Book data is automatically fetched from Amazon Web services. Manual book entry is possible for non-catalogued books. Bookshelf design is done graphically with the Cairo drawing library, and is based on the most efficient book order.
Crowd is a Web-based single sign-on (SSO) tool that simplifies application provisioning and identity management. It has connectors for popular open source projects like Apache (via Perl) and Subversion. Pre-built connectors for other popular commercial products like Jive Forums, JIRA, and Confluence are also available.