KDenLive has been a lifesaver to me. Very very impressive program!!

I keep discovering new features and ways to work with it.

Using full HD 1080p60fps video is no problem, splicing together a hundred clips is no problem... very stable, rarely crashes...
Been using it to make videos for an upcoming game: http://www.indiedb.com/games/dont-be-patchman

If there is a way to donate to KDenLive, I did not see it.

Thank you.