Tv's cobweb: Snakepit and gitosis, things I've been working on
HiveDB is an open source framework for horizontally partitioning MySQL systems. Building scalable and high performance MySQL-backed systems requires a good deal of expertise in designing the system and implementing the code. One of the main strategies for scaling MySQL is by partitioning your data across many servers. While it is not difficult to accomplish this, it is difficult to do it in such a way that the system is easily maintained and transparent to the developer.