TomP2P is a P2P-based high performance key-value pair storage library. Each peer has a table (either disk-based or memory-based) to store its values. A single value can be queried or updated with a secondary key. The underlying communication framework uses Java NIO to handle many concurrent connections.
nioReactor is a framework for quickly building scalable event-driven network applications. It is built on top of the Reactor design pattern using NIO sockets. This provides high performance and allows for a complete separation from the application specific code. The goal of the project is to provide a simple set of APIs that allow users to build scalable servers without needing to deal with with the cumbersome and sometimes temperamental peaces of the NIO package.
io-util is a small, scalable Java library for slicing and dicing fixed width tables on disk. The objective is to provide reusable blocks of code for building efficient, custom binary data stores. It allows you to build, search, and maintain a large, externally stored, fixed width, sorted table. The library user specifies the row width (in bytes), a row comparison function (which implicitly defines any given row's key), and an optional delete codec.