of terrain and coordinated strikes around dusk or dawn. The Islam-inspired Khalifate faction is still under development. Development David White began development of Wesnoth because he wanted to create a freely available, open source strategy game with very simple rules, but one that had difficult to beat artificial intelligence and that was challenging and fun — a game that was easy to learn but hard to master. The game is programmed in C++. It is cross-platform, and runs on AmigaOS 4, BeOS, FreeBSD, Linux (including OS flavors running on GP2X and Nokia n800, n810, and n900 handheld devices), OS X/Darwin, Windows, MorphOS, NetBSD, OpenBSD, RISC OS, iOS, Solaris/illumos, Android, Playbook and Google Native Client running under Google Chrome. Wesnoth development is decentralized due to its free and open-source nature. The officially blessed campaigns and units bundled with the game download are often derived from content created by the community, somewhat differently from the user-generated content in proprietary games where such content, while available, is usually not incorporated into official builds of the game. The Wesnoth forums and wiki are used to develop new campaigns, including new unit types and story artwork. The game is able to download new campaigns from a central add-on server. Content featured on the official campaign server must be licensed under the GNU GPL-2.0-or-later, like the game itself. Even when not counting this community content, the list of contributors to the official version of the game as displayed in-game contains over 550 unique entries (May 2010). Developers of the game also include well-known authors from the free software and open source scene, like the co-founder of the Open Source Initiative and core Linux kernel developer Eric S. Raymond, or Linux kernel programmer Rusty Russell. As of April 2010, The Battle for Wesnoth is available in about 50 languages, 9 of which have more than 90% of messages translated. Active developers As of September 2015, The Battle for Wesnoth announced their development team consisted of no more than five developers. On the homepage for the game, the reason for a lack of bug fixes was explained, "Sadly, a hard truth must be faced: Wesnoth, as a project, is understaffed. At this time, there are fewer than half a dozen developers working on each new version of the game, and even fewer of them are able to work on the engine itself". Art The art development team was