Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
You can capture video of all of the amazing things happening on your desktop with one of Linux's many screencasting applications. These programs are perfect for creating demonstrations for blogs and tutorials, and for illustrating projects with more than just still images.
Many different programs are available, and they all provide a different set of features, options, and output formats. When choosing, consider the degree of control you want to have over your video resolution and whether the video is intended to work on non-Linux operating systems. Common open source output formats, such as FLAC and Ogg Theora, work natively on Linux but require software and plugins on proprietary operating systems. User interfaces also vary greatly; some applications are nothing more than an icon in the system tray while others depend on large interfaces with many options.
I tested three popular screencasting applications to see which is best for everyday use. I evaluated the user interface, the quality and variety of output formats, and the ease of installation and obtaining the required dependencies. I tested the programs on a MacBook Intel Core 2 Duo with 4GB of RAM, dual-booting into Ubuntu 8.04 Hardy Heron.