Framework Overview:
Xamarin is one of the leading open source cross-platform development framework which uses C# as the programming language is backed by Microsoft. Xamarin was founded in 2011 and was acquired by Microsoft in 2016, which later made it an open source platform, and now it has become an integral part of the Xamarin Visual Studio IDE.
Flutter is also an open source free cross-platform development framework tool which uses Dart as the programming language and is designed by Google to create high performance Android and iOS Mobile Applications. It provides a single code, which is also the case in Xamarin.
Technical Architecture:
For its iOS and Android platforms, Xamarin uses Mono as it execution environment. In iOS platform, Mono runs along with the Objective-C on UNIX kernel, however, in android it runs along with Android run time on Linux. As its backed by Microsoft, Microsoft has provided a detailed documentation to technical architecture used for Android and iOS in Xamarin.
The Dart framework of Flutter uses Skia engine which is bigger in size as it has most of the components inbuilt and hence, usually doesn’t require a bridge to communicate with the native modules. The architecture of Flutter is explained in detailed in GitHub wiki. Overall, Flutter has a better technical architecture in place than Xamarin as it has most of the native components inbuilt in its framework itself.
Community Support:
Since Xamarin is an old cross-platform framework, it has huge community base all across the world. There’s a huge number of developers who uses Xamarin and hence, it is has a huge community forums to discuss the issues, problems, events, updates etc. Xamarin also actively organizes events like Xamarin development summit to keep its community active and strong.
Though Flutter is new, but the growth it is shown is very promising. It actually started gaining developer’s attention only after 2017. Even Flutter is organizing events like meet-ups, conferences and Flutter Live to keep increasing it developer base. Though rapidly growing, Flutter has a developer base which is lot lesser than Xamarin.