in June 1993. Alexandre Julliard has led the project since 1994. The project has proven time-consuming and difficult for the developers, mostly because of incomplete and incorrect documentation of the Windows API. While Microsoft extensively documents most Win32 functions, some areas such as file formats and protocols have no publicly available specification from Microsoft, and Windows also includes undocumented low-level functions, undocumented behavior and obscure bugs that Wine must duplicate precisely in order to allow some applications to work properly. Consequently, the Wine team has reverse-engineered many function calls and file formats in such areas as thunking. The Wine project originally released Wine under the same MIT License as the X Window System, but owing to concern about proprietary versions of Wine not contributing their changes back to the core project, work as of March 2002 has used the LGPL for its licensing. Wine officially entered beta with version 0.9 on 25 October 2005. Version 1.0 was released on 17 June 2008, after 15 years of development. Version 1.2 was released on 16 July 2010, version 1.4 on 7 March 2012, version 1.6 on 18 July 2013 and version 1.8 on 19 December 2015. Development versions are released roughly every two weeks. Wine-staging is an independently maintained set of aggressive patches not deemed ready by WineHQ developers for merging into the Wine repository, but still considered useful by the wine-compholio fork. It mainly covers experimental functions and bug fixes. Since January 2017, patches in wine-staging begins to be actively merged into the WineHQ upstream as wine-compholio transferred the project to Alistair Leslie-Hughes, a key WineHQ developer. , WineHQ also provides pre-built versions of wine-staging. Corporate sponsorship The main corporate sponsor of Wine is CodeWeavers, which employs Julliard and many other Wine developers to work on Wine and on CrossOver, CodeWeavers' supported version of Wine. CrossOver includes some application-specific tweaks not considered suitable for the upstream version, as well as some additional proprietary components. The involvement of Corel for a time assisted the project, chiefly by employing Julliard and others to work on it. Corel had an interest in porting WordPerfect Office, its office suite, to Linux (especially Corel Linux). Corel later cancelled all Linux-related projects after Microsoft made major investments in Corel, stopping their Wine effort. Other corporate sponsors include Google, which hired CodeWeavers to fix Wine so Picasa ran well enough to be ported directly to Linux using the