Streaming audio can also be done with a Java applet. Special hardware or software is required to convert, although some video cards may be able to convert directly. Not all browsers may recognize the HTML tag. Often none, although drivers to play certain video files may not always be installed. Special hardware or software is required to convert.
Some video cards can convert directly.
The .MPEG and .QT3 files have more compression than .AVI files, but can still run into 100's of megabytes. Still, they may be a good alternative for small clips. Typically a downloadable browser add-in. Special hardware or software is required to convert. RealPlayer is sometimes pre-installed on computers these days, saving your visitors the time to download it.