RE: Science, Technology, Engineering & Mathematics powered by Hive

None of those things, it's just templates with service subscription and reseller license. If I'd have to do that myself I'd go with Blender and most likely spend so much time on that trying to make it perfect that I wouldn't never finish it ;-)

GIF is just postprocessing of the source video material, it's tricky because you have to keep minimal viable quality and yet fit in a reasonable file size.