I know that .NET 4 is on the roadmap. As we discussed, the biggest problem with 3.5 (that I know of) is the lack of support in Service Center. :(

J.Ja

I've done some work trying to compile current 5.1 Outsystems output in both 3.5 and 4.0 - 3.5 seems easiest (without changing the generators) as there are several classes that have been removed or changed in 4.0 framework that the current  code relies upon.

Hopefully, 3.5 can therefore come fairly quickly with 4.0 later.

.Net 3.5 is supported. 4.0 on the roadmap (but since 4.0 is not compatible with 3.5 and lower, that means that we need larger adoption of it in our customer base in order to break compatibility...)