The J# (pronounced 'jay-sharp') programming language is a transitional language for programmers of Sun's Java and Microsoft's Visual J++ languages, so they may use their existing knowledge and applications on Microsoft's .NET platform. J# can work with Java bytecode as well as source so it can be used to transition applications that use third party libraries even if their original source is unavailable. Java and J# use the same general syntax but there are non-Java conventions in J# to support the .NET environment. Visual J# is part of the Visual Studio software suite.
According to their website, Microsoft retired the Visual J# product and Java Language Conversion Assistant tool to better allocate resources for other customer requirements. The J# language and JLCA tool will not be available in future versions of Visual Studio. To preserve existing customer investments in J#, Microsoft will continue to support the J# and JLCA technology that shipped with Visual Studio 2005 through to 2015 as per our product life-cycle strategy.