A long timer reader asked in the forum if I knew of a program that would be able to join mp4 files. I was not able to give the answer immediately but after a short research I found a program called Yamb which is able to join, split and create mp4, mov and 3gp files. You do need the mpeg 4 converter mp4 box because Yamb uses it for the conversions. Yamb is mainly a gui for mp4 box, the hardcore users could simply use the command line to work with mp4 box, all others should better use Yamb.