Microsoft Silverlight - Mono Moonlight Implementation

Mono Moonlight Implementation

The Mono team abandoned development of Moonlight, a free and open-source implementation of both the Silverlight 1 and 2 runtimes.

The development has been discontinued as of 2012 due to the poor acceptance of Silverlight and restrictions Microsoft imposed on its utility.

The project was officially supported by Microsoft who, under an agreement with Novell, has made additional specifications, access to the Silverlight Base Class Library APIs, binary codecs and test cases available to the Mono team, none of which are available to other members of the public.

The "covenant" under which Novell has been granted this exclusive access also specifies conditions that are incompatible with the licensing that covers most other free and open source software. As examples, it specifically requires that the software must have been "obtained directly from Novell or through an Intermediate Recipient" and that it must be "not licensed under GPLv3 or a Similar License". Some free software proponents have criticized the covenant.

Silverlight has received criticism for not living up to its cross-platform operating system compatibility promises, especially on Linux systems compared to its extensive support on Apple and Microsoft desktops for Internet Explorer, Firefox, and Chrome. Even though Microsoft was officially collaborating on the Moonlight project, Bruce Chizen, who was CEO of Adobe Systems at the time, which sells the competing proprietary Flash platform, questioned "the commitment of Microsoft to keep the Silverlight platform compatible with other OS besides Windows". His concerns are based on "examples from history" where, he argues, Microsoft has launched products with promises of ongoing cross-platform compatibility that no longer apply, for example Internet Explorer for UNIX and Windows Media Player for Mac.