Concerted is a highly scalable multivariate in-memory data storage library. It has built in support for multivariate queries and performs well over many styles of workloads. The data is read and stored in various data structures, and the data from data structures written to disk. It is fully ACID compliant, has APIs that abstract details from the user, and provides an easy to use interface. Many different types of indexes are provided along with various systems that provide access for data analytics.
Aurora-Sim is the next generation of the OpenSimulator Project. It allows you to run a large scale operation and extend it as needed, while still having many features available for your use. The architecture is designed to be as flexible as possible so that third parties can create modules by plugging into the modular design. It is cross-platform compatible by using the .NET framework and Mono. Most importantly, it is a community based project consisting of individuals with a variety of talents (technical and non-technical) and has been developed with an emphasis on security, speed, and performance.
Immutable Collections for Java is a library providing immutable/persistent collection classes for Java. While collections are immutable, they provide methods for adding and removing values by creating new modified copies of themselves. Each copy shares almost all of its structure with other copies, to minimize memory consumption. The library includes a singly-linked (cons/cddr style) list/stack, an integer tree-based indexed list, a 2-3 tree-based random access indexed list, a 2-3 tree-based map, a hash tree-based map, and hash- and tree-based sets. All collections provide immutable Cursor as well as standard Iterator classes for looping through all elements. A utility class provides functional style algorithmic processing of Cursors, including foldLeft, foldRight, collect, select, and reject. The 2-3 tree and integer tree classes are optimized for performance and can be used alongside java.util Collections when immutability is needed for safe data sharing.