Is there a video type for vector animation? Is there a vector-based video type, preferably open-source, so that an animated clip could be produced using "rules" instead of pixel-compression?

This would mean lossless resolution-independent video. If it does exist - a link to the specifications would be helpful.
There was one, but it fell in to disuse and isn't used very often anymore, largely because of the lack of mobile support, but also due to security issues it created.  It was called Flash.