From the site:
"Zamzar is dedicated to helping you transform your songs, videos, images and documents into different formats. Our mission is:
'To provide high quality file conversion for as many file formats as possible'
We are intent on bringing order to your filesystem by offering you a one stop solution for all your file conversion needs. Like others we were fed up with having files in all sorts of formats, and no easy way of converting between them - the quest to find a better way led to the birth of Zamzar."