I was finding that running appstream-util validate-relax against the appdata file shipped with 0.14.22 was error'ing out due to the lack of a terminating period for the second description paragraph on Fedora 20-22. While fixing that, since it was open in the editor I made what I think are improvements to the text - the original text was very sparse, and the summary required the user to know what "Screen" is, and if they didn't would leave them scratching their head, as screen is a generic term to most people. Anyway, patch attached in case it's useful.
Applied to both branches in r9177, so this will be included in 0.14.24 / 0.15.0. Thanks!
For reference, the original appdata ticket is here: #730.
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/844