Yesterday I came across this :
Also interesting to me is "the effort to implement SMIL for Firefox". But 'interesting' in a different way as I actually once did a SMIL project … many years ago during my studies. Hmm … *thinking* … no idea when, maybe in 2000?? I don't know. What is SMIL, you may wonder? It's a W3C standard …
The Synchronized Multimedia Integration Language (SMIL, pronounced "smile") enables simple authoring of interactive audiovisual presentations. SMIL is typically used for "rich media"/multimedia presentations which integrate streaming audio and video with images, text or any other media type. SMIL is an easy-to-learn HTML-like language, and many SMIL presentations are written using a simple text-editor
Back then there were no freely available players that actually implemented the whole specification. We tried the Quicktime-Player and the RealPlayer. I know that there was a 3rd one, but I think you had to buy it. Quicktime had support for a really small subset and Realplayer was actually not fully compatible. We had to use not so few 'RealPlayer only' tags, but at the end we were actually able to do a little"rich-media" presentation and watch it using the RealPlayer.
The project was something like a simple web-based SMIL editor. Very simple. We had a HTML front-end where you were able to add media, transitions etc. Then the data was saved as SMIL. The editor was able to load SMIL back for further editing.
I am not sure, if there is nowadays really a need for this. Flash or the combo "HTML, CSS, JS" does the trick.