The Valve Developer Community, a resource devoted to authors of mods using Valve's Source engine (the technology that powers Half-Life 2 and Counter-Strike: Source), alongside the Steam content distribution system, has opened to the public. The system is intended to be a pool of knowledge that mod authors can contribute to, as well as consult for advice on how to use the robust Source engine. The Community is built using MediaWiki, an open-source GNU tool for allowing entries and posts to be edited and refined by anyone with an account. The same technology powers the popular Wikipedia, an online encyclopedia. Though the focus of the site is on Valve-owned properties and engines, some more general-purpose entries have already begun to crop up. An account is necessary to edit entries, but all entries are freely available to read without an account. Valve Software has historically been extremely encouraging of mod developers, with one of the company's leading products, Counter-Strike having initially been developed by modders, and subsequently acquired by the company.