Xdelta is a tool and library for differential compression. Xdelta release version 3 supports VCDIFF encoding and decoding. Supports compressing 64 bit files on Windows, Linux, etc.

Xdelta 3.0 is a stable release and being actively developed.

Xdelta 1.1.4 is a maintenance release. Xdelta 1.1.0 was released in 1999.