Desurium
Desurium is a game-targeted digital distribution platform by DesuraNET, and is the free software project founded to be the core part of their Desura product; in a similar matter to Google's Chromium project in relation to Chrome. All source code is available under the GNU General Public License version 3. Various free software games were available from the Desura service, such as Abuse, Battle for Wesnoth, Neverball, Neverputt, OpenTyrian, OpenTTD, OpenArena, Tremulous, and Xonotic; and quite a few others that have source code released but are not truly free.
The parent company of Desura went bankrupt in 2015[1]. As the program is still set to be tied to their proprietary server infrastructure[2] which is no longer available, it is not of much use to players unless someone were to set up an independent alternative service.