SMIL stands for Synchronized Multimedia Integration Language, and is pronounced "smile". It is a way to combine images, audio, animation, and text into a presentation that will let you display them on other peoples computers the way you designed them.

SMIL 1.0 is an official W3C recommendation, and will be included in the next generation of browsers. The first versions of this showed up in MSIE5.5 and Netscape6, but neither meet the W3C specification since they include proprietary calls. But you can use plugins or applets to use the true SMIL specification. The SMIL 2.0 specification, also known as SMIL Boston, is finalized now and extends its functionality. The browser version that natively supports it is pushed back a few more itterations, but again, plugins come to the rescue.

SMIL provides:
Spatial Layout
Timing Relationships, or Synchronization
Inclusion of media beyond Text and Image files
Hyperlinks in time-based media
Adaptations to User and System details.

The Goal (or one of them, they are doing a LOT online!) of the W3C is to have all SMIL content playable on all players, with changes for media formats. But various Media types compress into faster downloading and displaying than the basics, and each SMIL Player has its own advantages, so you must tune your SMILs for the media types that make sense to you. With luck, these pages can give you the basic info and tools you need to build your own SMILs.

The Demo link here has several different flavors of SMILs, most of which will show up as various Java Applet embeds on a web page. A few others require proprietary filetypes, so can only launch in specific players. By the time we are done here, you should know how to build each of these, in all their variations.

If you have RealPlayer installed, you can check out the first RealMedia SMILs of this set. They have simple structures, to show the basics of building SMILs. A Text-N-Image display, a slideshow with an audio trac built along a timeline, that sort of thing. They include media types and transitions that are proprietary to their plugin format, but you can do the same thing in most SMIL players. They just might take a bit longer to download.