http://www.cinepaint.org/more/docs/funding.html
Believe it or not, government and the private sector do fund open source projects they're interested in.
Just because it's free doesn't mean it has competition either.
Open source doesn't mean free crapware. It's just open source. Plenty of profiting businesses release open source projects as well.
I interned at a place that would take contracts, gather funding, and release open source. It can be a money making business model.
Cinepaint was forked from GIMP a while back and supports high bit-depth image formats as well as .psd files (with a plug-in that comes with the program when you build/install it). It still isn't industry standard but supposedly sees some use in the film industry.
i came across CinePaint ( http://www.cinepaint.org/ ) but i haven't tried it yet. it says that it is based on gimp but with 32 bpc support. it sounds promising but the website looks pretty crappy. so i don't know what to think about the software, but maybe you can use it
cinepaint will do 16 bits per channel and can do CMYK color. it's based on a older version of the GIMP though (requires GTK v1), so that could be an issue.
otherwise you could wait until gimp 3.0 (which should happen sometime in our life times....)
FWIW, the CinePaint fork is still around. Apart from having a far more marketable name than GIMP, it does HDR. Though it has its own UI problems, having been originally forked from an old version of GIMP.
I remembered that I've used Cinepaint a few times. It's a fork of an older GIMP version but it will edit at 16 and 32-bits per channel unlike GIMP which is 8-bit only (for now but changing with GEGL)
Yes, as long as Gimp can open it, you can do it. I've used Gimp for just about every gif in this directory http://files.samhart.net/humor/
Bear in mind, any video file that Gimp can open (supported format, etc. and so on), Gimp will convert to its internal format in memory. This means that each and every frame will be stored, decompressed, in memory as a layer. This will be memory intensive even for the smallest clip.
My recommendation, unless you have an ungodly amount of RAM, is to edit the clips down to exactly what you want in an external, dedicated video editor first, rescaling them to the appropriate size, and then use Gimp for the final conversion to gif. The reason for this is because Gimp isn't a video editor, it's an image editor. It's simply not optimized for editing of video files.
Years ago, there was a fork of Gimp for use specifically in video editing (IIRC, it was originally made for use in the Scooby Doo movies, but I may be remembering wrong) called 'FilmGimp'. It has since been renamed as CinePaint. It's probably more optimized for editing/handling video than normal/stock Gimp, but for creating your basic 3-5 second animated gifs, it's also probably total overkill.