ENet for C# wraps the C-language ENet networking library. For games and other realtime applications, if you use TCP, old data can hold up newer data, even if it is no longer relevant (old positions, etc.). Your players will perceive any lost packet as a "lag burst". ENet supports multiple in-order streams of data, and allows you to decide on reliability on a per-packet basis. The library is useful for both client-server and peer-to-peer architectures.
RoseThorn is a cross-platform library for 2D and 3D games running on GNU/Linux (and possibly other Unix-like OSes) and Windows. Features include: hardware accelerated 2D and 3D rendering; Ogg and WAV Sound support with OpenAL; Lua scripting; BMP, JPEG, and PNG image loading and saving (from screenshots); easily created and modified user interfaces with XML and CSS, combined with Lua event handling; separate 2D and 3D libraries; support for multiple fonts in both TTF and bitmap formats; support for OBJ, 3DS, MD5, and RTM model formats; skeletal animation (a work in progress); support for UDP and TCP networking; thread and mutex support; a Simple Shader API; 2D animated sprites; and some basic cryptography support. There is simple event management, with key/mouse bindings easily customized from the in-game console, config file, command line, or GUI.
gzochi is a framework for developing massively multiplayer online games. A server container provides services to deployed games, which are written in Guile Scheme, that abstract and simplify some of the most challenging and error-prone aspects of online game development: Concurrency, data persistence, and network communications. A very thin client library can be embedded to provide connectivity for client applications written in any language.
crunch/crnlib is a lossy texture compression tool and library for developers that distributes and uses content in the DXT1/5/N or 3DC/BC5 compressed mipmapped texture formats. crnlib can compress mipmapped 2D textures and cubemaps to .8-1.25 bits/texel, and normal maps to 1.75-2 bits/texel. crnlib's quality and performance is competitive to transform-based solutions, or other offline/real-time DXTn compressors such as squish or ATI_Compress. crnlib implements a new form of "clustered" DXTn compression, with a compressed texture data format that was carefully designed to be very quickly transcodable directly to raw DXTn texture bits with no intermediate recompression step or individual pixel-level operations. The typical single threaded transcode to DXTn rate is equivalent to 100-250 megatexels/sec. Fast random access to individual mipmap levels is supported.
The Gluon project is an open framework for creating and distributing games, supporting the flow of the idea all the way from the author to the player of the finished game. The current goal for the first stable release is to create games using 2D graphics. The reasoning behind this is that the niche for this type of visual is very large and so far untapped by specialized tools. In the world of 3D games there are solutions such as Unity3D, which provide a distribution system, but in the 2D game development world there are no tools to provide a complete ecosystem for creation, distribution, and feedback gathering. The three main audiences of Gluon are game creators, game players, and application programmers. Each of these are a user of one of the tools.