I wanted to give an update on the Mono support. As of version 1.2.5 of Mono (version soon to be released) we can say that Eiffel assemblies will work smoothly with Mono. Our last regression test for the compiler targeting Mono is only failing 20+ tests that the Microsoft .NET runtime is accepting (over 1350+ tests).

We have an Eiffel for .NET dll which is called by a VB.NET application. We need to internationalize this application. "That should be easy", I thought, "because Eiffel's STRING is basically just a wrapper for the .NET String." So we fed our Eiffel dll some UTF-8 data, which it dutifully manipulated; but the VB.NET client application received garbage. Instead of displaying beautiful Farsi characters, it spat out wingding-dingbat-like droppings. What was wrong?

Until very recently, EiffelStudio generated .NET assemblies would not work with Mono. The culprit was the usage of the #- metadata table format (a non-standardized Microsoft .NET extension which allows specification of the metadata out-of-order) that Mono did not support.