Visual J Sharp

Visual J# (pronounced "jay-sharp") is a discontinued implementation of the J# programming language that was a transitional language for programmers of Java and Visual J++ languages, so they could use their existing knowledge and applications with the .NET Framework.^[1][2] It was introduced in 2002^[3] and discontinued in 2007, with support for the final release of the product continuing until October 2017.

J# worked with Java bytecode as well as source so it could be used to transition applications that used third-party libraries, even if their original source code was unavailable.^{[citation needed]} It was developed by the Hyderabad-based Microsoft India Development Center at HITEC City in India.^[4][5]

The implementation of Java in Visual J++, MSJVM, did not pass Sun's compliance tests leading to a lawsuit from Sun, Java's creator, and creation of J#. Microsoft ceased such support for the MSJVM on December 31, 2007 (later Oracle bought Sun, and with it Java and its trademarks). Microsoft however, officially started distributing Java again in 2021 (though not bundled with Windows or its web browsers as before with J++), i.e. their build of Oracle's OpenJDK,^[6] which Microsoft plans to support for at least 6 years, for LTS versions, i.e. to September 2027 for Java 17.