1) Windows Movie Maker
This can usually be found pre-installed on your computer. If you can’t find it there, you can always reference Microsoft’s website to download a copy right onto your system.
2) Camtasia (Compatible with both PC and MAC)
NOTE: Editing MP4 files - If you have Camtasia V6.0.1 or higher you should have no problem as shown on their update history here: http://www.techsmith.com/camtasia/history/win/#601
Note: 6 January 2009: v6.0.1 Maintenance Release
General - Added the ability to include and edit .MP4 files on the timeline.
Here's a link to Camtasia's training site: http://www.techsmith.com/learn/camtasia/7/
3) Screenflow (Compatible and Recommended for MAC users)
If you are a MAC users, we actually recommend that you use screenflow. You can use Camtasia on MAC computers, however you will want to try the Trial version first to ensure it works properly on your computer. Camtasia is known to crash on the MAC.