This fork of Joshua MacDonald's Xdelta (Apache licensed fork) is formatted as a library / go wrapper for the xdelta3 API. It's really version 3.0.11, but had to do some minor changes in order to make in compatible with the Go (cgo) compiler and to make it a library.
Xdelta version 3 is a C library and command-line tool for delta compression using VCDIFF/RFC 3284 streams.