H.264 is a codec so its not “really” a video file format. If you are searching for H.264 Editing Software then you really should be…
…looking for video editing software like Sony Vegas and Adobe Premier or Apple Quicktime.
The codec is the way the video is compressed, so when using Quicktime you have a choice of codec which you can use to encode your movies with and this includes H.264.
If you want to talk real techy:
H.264/AVC is the latest block-oriented motion-compensation-based codec standard developed by the Video Coding Experts Group (VCEG)
But we don’t need to worry about that….
