Gifcurry is the open-source video editor for GIF makers. It's built with Haskell and works on Linux, Mac, and most likely Windows. There is both a graphical and command line interface.
Gifcurry edits your GIFs or videos and turns them into videos or GIFs. You can crop, trim, seek, add text, pick a font, alter the duration, change the size, set the FPS, tweak the color count, enable dithering, import subtitles, and save your creation as either a GIF or video.
For Mac users, head over to the read me page and follow the instructions. Eventually there will be a Homebrew formula so installing Gifcurry on the Mac will be super easy.
Gifcurry hasn't been tested on Windows yet but there's no reason it shouldn't work. If you know how to build Haskell programs, go to the read me page and follow the instructions.
Found a bug? Need a feature? Can't install it? No worries. Point your browser to the issues page.