I notice several well-known projects in java that were ported to C# .NET. Some examples: Hibernate - NHibernate JUnit -- NUnit Ant -- NAnt Lucene -- Lucene.Net, NLucene iText -- iTextSharp log4j -- log4net Quartz -- Quartz.NET I was curious about the reverse situation: what are the notable .NET projects that have been ported to the java world? I looked at the list of projects at http://csharp-source.net but didn't see any obvious ones.