MaPit is our database and web service that maps postcodes and points to current or past administrative area information and polygons for all the United Kingdom. It has been rewritten from the ground up in GeoDjango and PostGIS, providing us with a large array of improvements including speed, a lovely admin interface, and much easier updating. The source code is available on GitHub.

This is a catalog of things UNIX-like/POSIX-compliant operating systems can do atomically, making them useful as building blocks for thread-safe and multi-process-safe programs without mutexes or read/write locks. The list is by no means exhaustive and I expect it to be updated frequently for the foreseeable future.