Visual J++ (pronounced "Jay Plus Plus") was Microsoft's specific implementation of Java. Syntax, keywords, and grammatical conventions were the same as Java's. Microsoft discontinued support of J++ in January 2004, replacing it to a certain extent with J# and C#.
J++ compared to Sun's Java implementation 
While J++ conformed to the Java language specification, Microsoft did not implement certain features of the official Sun Java implementation in its Visual J++ product line. Remote Method Invocation (Java RMI) and Java Native Interface (JNI) are such examples.
In addition, J++ implemented other extensions that were not part of Sun's Java implementation. The inclusion of callbacks and delegates for event handling further contributed to defining J++ as a completely different language merely based on an already existing design concept.
Furthermore, J++ applications did not conform to the standardized method of accessing the underlying operating system functions as any other Java application under Sun's Java SDK. In Microsoft's implementation, an underlying framework called J/Direct provided a base mechanism that allowed J++ applications to completely circumvent Java's class libraries and API media in accessing the underlying operating system. Due to this short-cut around the original Java framework, J++ applications were more efficient in taking advantage of Win32 API functions than Java applications.
J++ applications using these features could not be run on Sun's Java SDK, but the Kaffe project developed extensions which made it possible to run J++ applications with these features on their open sourced JVM. However, these extensions (implemented by TransVirtual under Microsoft funding) were not widely used, and J++ applications still needed to be compiled on Visual J++ before being able to be run by Kaffe.
The WFC 
The Windows Foundation Classes (WFC) encapsulated the Microsoft Win32 platform API and DHTML object models into a unified class library. WFC was primarily designed for creating graphical user interfaces for Java applications on Windows.
Sun's litigation against Microsoft 
Sun Microsystems had originally licensed Java to Microsoft but later initiated litigation against Microsoft for trademark violation. (Sun's trademark license for usage of the Java brand insists that all implementations be "compatible".)
The failure of the MSJVM to pass Sun's compliance tests was a large factor in the initial lawsuit. On January 24, 2001, this and all other outstanding Sun-Microsoft lawsuits were settled as part of a wide-ranging agreement between Sun and Microsoft. The settlement document outlined that Microsoft also could not advance J++ beyond its mirrored implementation of Java, version 1.1.4. This effectively ended J++ and further updates. As well, the MSJVM had to cease to be distributed and is no longer available for download.
However, due to settlement of outstanding litigation, Microsoft was allowed further to update the MSJVM to fix security holes and any problems relating to the security threat. Microsoft has since ceased support for the MSJVM on December 31, 2007.
Visual J++ - The IDE 
Visual J# 
Visual J# (pronounced "Jay Sharp") is a Microsoft language whose syntax is close to Java, part of the .NET Framework. Visual J# is part of the Microsoft Visual Studio .NET product suite and is designed to help developers and programmers migrate from J++ (or Java) to the .NET Framework.
Microsoft later developed the C# ("C Sharp") language as the primary language for the .NET platform, which was in many ways influenced by Java; subsequently the .NET Framework shares many ideas in common with Java. Much like Java, C# is compiled to a type of bytecode (called CIL), and runs on top of a virtual machine called the Common Language Runtime in .NET. Visual Studio 2005 was the last release to include J#.
- "JFC; Microsoft declares war". xent.com. 1997-08-01. Retrieved 2007-07-14.
- "Microsoft's J/Direct called death of Java". JavaWorld. 1997-07-01. Retrieved 2010-11-20.
- "Transvirtual Adopts Microsoft Java Extensions". linuxjournal.com. 1999-01-10. Retrieved 2007-08-01.
- "Java-Clone Announced". slashdot.org. 1999-06-14. Retrieved 2007-08-01.
- "MS debuts Visual J++". CNet. October 1, 1996. Retrieved 31 October 2011.
- Lohr, Steve (1998-05-25). "Still Another Adversary for Microsoft". New York Times. Retrieved 2009-03-15. "A September 1997 E-mail message, sent by a Microsoft official identified as P. Sridharan, is quoted as saying: "Let's move on and steal the Java language. That said, have we ever taken a look at how long it would take Microsoft to build a cross-platform Java that did work? Naturally, we would never do it, but it would give us some idea of how much time we have to work with in killing Sun's Java.""
- "Microsoft A History of Anticompetitive Behavior and Consumer Harm". European Committee for Interoperable Systems. 2009-03-31. Retrieved 2009-04-22. "We should just quietly grow j++ share and assume that people will take more advantage of our classes without ever realizing they are building win32-only java apps."
- "Sun settles with Microsoft, announces layoffs". www.news.com. 2004-04-02. Retrieved 2007-10-03.
- "Microsoft Java Virtual Machine Support". Microsoft. 2007-03-02. Retrieved 2007-10-09.