SMIL - standard

SMIL

Synchronized Multimedia Integration Language

W3C

https://www.w3.org/AudioVideo/

https://www.w3.org/TR/SMIL/

https://www.w3.org/TR/REC-smil/

SMIL 3

https://www.w3.org/TR/SMIL3/

SMIL 2.1

https://www.w3.org/TR/SMIL2/

SMIL Animation

https://www.w3.org/TR/smil-animation/