With their focus on Xamarin, the commercial version of Mono, it often seems like Mono is being is being neglected. But the nine year old platform is still seeing active development. For cross-platform developers the most important change is probably support for Portable Class Libraries. This is the technology that allows a single DLL to be used by a combination of .NET, Windows Store, Windows Phone, and/or Silverlight.
Those who use Linux to reduce their production server costs will be happy to learn that the new version of Entity Framework is being shipped in box. Entity Framework became an open source product last July and began shipping with Mono a month later. Cookies are now supported in WCF, which removes some of the burden in sending session data from the browser.
A somewhat surprising announcement is the SGen improvements. Apparently SGen wouldn’t release memory back to the operating system even if the application no longer needs all of the RAM allocated to it. For most applications this probably isn’t a concern, but if your application occasionally needs lots of memory for only a few minutes this could be frustrating.
Another long overlooked feature is support for WeakReference<T>, which was added in the interim build 3.0.8. While rarely used directly, this can be quite important to framework designers.
For OSX users, Mono officially supports MacOS X Mavericks and has fixed the LLVM loadable module issues.
You can see the full release notes for Mono 3.x on the project site.
