Hard to answer this question due to the number of possible answers but you can try the following:<p>Testing: xUnit or nUnit. FsCheck, Fuchu and FSpec, if you want to try a more functional approach. SpecsFor, BDDfy, Fixie, Machine.Specifications for BDD and other approaches.<p>Mocking: NSubstitute or FakeItEasy<p>Database: Simple.Data, PetaPoco, Massive for Micro ORM's. Entity Framework and nHibernate for full featured ORM's.<p>Build: There isn't a Maven/Gradle comparison but you can use NuGet, MSBuild, Fake, pvc build, etc.<p>Logging: ELMAH, NLog, Glimpse, Serilog<p>If you need other suggestions, let me know.