Converting Video on the Mac
In the Past converting video was a complicated process for people with a technical know-how of codecs and convoluted jargon that only experts understood. With the evolution of video on the internet, various developers have simplified the process down with some easy to use applications, which the average person can utilize.
The list is long across all the mainstream platforms. However, I live in the Mac world for all my graphics/web and Visual Effects work. The two most common applications I end up using for converting between video formats are FREE.