GNU Classpath is a free software implementation of the standard class library for the Java programming language.

When the Classpath project began, the license for the official Java implementation from Sun Microsystems did not allow distribution of any alterations.

Since the inception of the Classpath project, the OpenJDK was released under the GPL and now serves as the official reference implementation for the Java platform.

[citation needed] During the history, it merged several times with other projects having similar goals (Kaffe, libgcj).

As Classpath was becoming a base library, shared with a lot of different projects, this virtual machine received less and less attention and is now no longer supported.

The development speed (computed mathematically as the average number of the new lines of code per day) reached its highest ever in 2006.

[citation needed] The name GNU Classpath was originally suggested by Bradley M. Kuhn to one of the first developers, Paul Fisher.

The standard Java API contains numerous classes from the omg.org domain that are normally generated from the IDL files, released by the Object Management Group.

For this reason, the mentioned classes in the GNU Classpath project were written from scratch, using only the official printed OMG specifications.