J# is a programming language that was developed by Microsoft as an extension of Java. J# was released in 2002 as part of Visual Studio .NET.
J# is syntactically similar to Java, but it also includes features from C#. J# can interoperate with existing Java code and libraries.
J# is not as widely used as Java or C#, but it is still used by some developers for creating applications that run on the .NET Framework.