many video decoders are usually included with video players, e.g. quicktime, which may be free. the h264 decoder is included in qt7. but video encoders sometimes hafta be paid for, especially the newer geek codecs. it's one of the big drawbacks of internet video - one never knows what geek codec is gonna be used, when one is given a link to somebody's new poser video. one on hand, nobody is obliged to view videos encoded with the latest codec, but on the other hand, the folks who wrote the codec have the right to be paid for their work, unless of course nobody uses it, in which case they'll just join the ranks of the dozens of other useless codecs out there.