RedDwarf Server is an open source middleware solution for developing the server-side of massively multiplayer online games. It is the official community fork of Project Darkstar, an open source project that was supported until 2010 by Sun Microsystems. Upon Oracle's acquisition of Sun, support for Project Darkstar was stopped. To continue development of the project, the community rebranded the latest codebase of Project Darkstar's repositories and released it as RedDwarf Server.
Clients can communicate with the server using a Java or C API. The community has also released client APIs for additional platforms including C#, Python, Objective-C, and ActionScript.
RedDwarf Server uses a built-in protocol for network communications. This protocol, currently limited to TCP communications, is outlined in RedDwarf's server documentation.
RedDwarf inherited the Project Darkstar licensing scheme, with the RedDwarf Server distributed under GPLv2 and the server APIs being made available under the GNU General Public License (GPL) with the classpath exception. The Java and C client APIs—available as part of the RedDwarf project—are distributed under a BSD license.