DivX is a video compression technology developed by DivX Networks, based on the highly efficient mpeg4 system.

The DivX codec (compressor/decompressor) allows you to create your own DivX files, or view them in a suitable media player, including the bundled player from DivX Networks itself.

DivX can be used for delivering trailers, but most people use it to sufficiently compress entire feature films so they can be transported on single CD-Roms or even over the internet.

At high levels of compression the quality is not as good as DVD, but it can get close - even when viewed full-screen.

As such, there are many official sources of commercial DivX material and, like most technologies, several unofficial ones too. There's even a DivX Player for a number of Pocket PC PDAs which, coupled with a 1GB IBM Microdrive, could let you watch a whole movie on the go.

The DivX codec is under constant development, so it's worth checking for updated versions once installed, for more efficient or better quality.

Version 6.1 is claimed to be up to three times faster then prevoius versions.