What application are you using to encode, and on what platform? I presume you are on Windows, since you installed Quicktime and "restarted" and expected to see new codecs. Quicktime does not register any codecs with Windows. You must use Quicktime's own player, editor, etc. in order to play or create Quicktime content. For creation, you must purchase Quicktime Pro. Quicktime does include several good codecs, but they are only accessible through the fairly poor encoding and editing interface of Quicktime, so if you are going to purchase a product for this purpose, it might be better to spend a little more money and get something a bit more fully featured. Your codec question itself seems like a simple one, but unfortunately it's not. There are many factors involved, and sadly those products that excel in one area are often the worst in others! For example if cross-platform and legacy support (playing on older systems and the widest variety of systems, including Linux) is important, you would probably use MPEG1, but the quality is not good, and the size is terrible! So in large part it depends on your audience - what platform are they on (or multiple), how good is their machine, are they willing to install new codecs or even players in order to view your movie? Etc. If you simply want the highest quality codec with the smallest file size, you probably want h.264. Quicktime has a pretty good implementation in the latest Quicktime 7, though I'm not sure the h.264 capability is in the current Windows version. There is also a free version of the h.264 codec that is in development and currently available for testing. Nero's video products also have an implementation of this codec. But the bottom line is it is still in early development and not many devices and players support it, so you would be limiting your audience by using it. h.264 is also more demanding on CPU resources when playing than any other codec, so it would not be good for slower machines. Divx is a fairly popular option, but because it is a commercial codec the free version is lower quality. Xvid is a free codec based on the MPEG4 standard - the same standard that Divx is based on - and it generally results in higher quality for equivalent file size than Divx (even the Pro version). Being free is also a nice bonus. ;) I personally recommend Xvid for general, high quality encoding in most cases, but it does require your audience to download the Xvid codec to play your video. A more generalized .mp4 (MPEG4 encoded video in a .mp4 standard container) is the best high quality container/encoding format currently available, and they can easily be created with Quicktime's own MPEG4 encoder, so if you want high quality, cross-platform support, that may be your best option. And if you already have a video editing solution and all you want to do is compress with another program/codec, the $30 Quicktime purchase may be worthwhile. - Oshyan