This was previously submitted to gentoo-ebuild@gentoo.org but was lost in the shuffle over to bugzilla. From the author's docs: Announcing version 1.1.3 of Xdelta. Xdelta is an application program designed to compute changes between files. These changes (deltas) are similar to the output of the "diff" program in that they may be used to store and transmit only the changes between files. However, unlike diff, the output of Xdelta is not expressed in a human-readable format--Xdelta can also also apply these deltas to a copy of the original file. Xdelta uses a fast, linear algorithm and performs well on both binary and text files.
Created attachment 37 [details] xdelta-1.1.3.ebuild
what would be a good category for this? dev-util/ app-misc/ ?
A good category for this ebuild would probably be dev-util. There are a couple of other types of diff-like utilities in dev-util already.
Added ChangeLog and COPYING to dodoc-line.
Added to dev-util/xdelta