We just released MonoTouch 4.0, a product to build iOS applications using C# and .NET. We also released our new Mono for Android product.
New in MonoTouch 4.0
MonoTouch 4.0 is a major upgrade to our product as it upgrades the Mono runtime engine from the old, trusted and friendly Mono 2.6 to the latest and greatest Mono 2.10 core, these are some of the new features available as part of this upgrade:
Parallel Frameworks for C#: Great APIs for building multi-threaded software. Not only this is great for iPad 2 users and developers, but it also simplifies just plain multi-threaded programming by exposing Futures, Tasks and Parallel LINQ to the developer.
LLVM Compiler Support: In addition to the fast Mono compilation engine, MonoTouch can now also use LLVM to create optimized builds. When you build MonoTouch applications using LLVM your executables will run faster, they will be smaller, and you can optionally opt into generating the nimbler ARMv7 or Thumb code (fat binaries are also supported).
Example: My own TweetStation distribution went from 8 megs to 6 megs using Thumb + ARMv7 support. A very significant gain.
C# 4.0 and .NET 4.0: This release comes with the latest incarnation of the C# language as well as exposing the new .NET 4.0 APIs (many new functional constructs make for nicer looking code, like all the IEnumerable enabled-methods in System.IO).
There is one important limitation: C# 4.0 dynamic support is not functional, since it requires dynamic code generation to work.
Upgraded WCF stack: We still consider this a preview of the full WCF but has been expanded significantly.
All new iOS 4.3 APIs have been exposed.
NSDecimal, NSDecimalNumber are now exposed (mostly for the sake of CorePlot :-)
Many new convenience APIs have been introduced.
For a full detailed list of changes, see our MonoTouch 4.0 Release Notes.
Read more: Miguel's OSX and iOS blog