- something like JavaScript? I mean adjusting and changing parameters without reloading the webpage
- video & audio tags accepting popular video formats like avi, wmv, mov, wma, wav, mp3...
- more parameters of video & audio like position of video/sound or parameter which is 1 if video/sound is playing and 0 if it is paused, but changable so you will be able to pause/play and seek video, change volume or something...
- image effects like blur, glow, opacity, shadow, bevel...
I know maybe some things I put there are stupid and definitely not nessessary

