The preview comes about a month and a half after the release of Moonlight 2, which shipped on Dec. 17 and also included some Silverlight 3.0 functionality, such as the Silverlight 3 Pluggable Pipeline, changes to animation functions, partial out-of-browser support and writable bit maps.
In a blog post about the Moonlight 3.0 preview, Mono project founder and Moonlight team member Miguel de Icaza listed new features in the preview release:
""??Ã MP4 demuxer support. The demuxer is in place but there are no codecs for it yet (unless you build from source code and configure Moonlight to pick up the codecs from ffmpeg).??Ã Initial work on UI Virtualization.??Ã Platform Abstraction Layer: the Moonlight core is now separated from the windowing system engine. This should make it possible for developers to port Moonlight to other windowing/graphics systems that are not X11/Gtk+ centric.??Ã The new 3.0 Binding/BindingExpression support is in.??Ã Many updates to the 3.0 APIs.""
Moonlight is an open-source implementation of the Silverlight development platform, which Microsoft describes as being "for creating engaging, interactive user experiences for Web, desktop and mobile applications when online or offline." Moonlight is intended primarily for Linux and other Unix/X11-based operating systems. In September 2007, Microsoft and Novell announced a technical collaboration that includes access to Microsoft's test suites for Silverlight and the distribution of a Media Pack for Linux users that will contain licensed media codecs for video and audio.
The Moonlight download site includes a security notice about the preview release:
""This release should be considered alpha quality. There are various new subsystems in Silverlight 3 (e.g. pixel shaders, local messaging, the client http stack) which expose new and different attack vectors, and the implementations of these subsystems have not yet been exercised or audited.As such we recommend that you should only use this plug-in on trusted sites (e.g. internal or well-known web sites) on non-production computers. This situation will gradually evolve over the beta releases. An up to date overview of Moonlight security features status can be found on Moonlight Security Status wiki page." "