KToon was designed for animators by the animators at Toonka. To use KToon, you need a CPU speed of 800MHz or more, at least 256MB of RAM, and 5MB of free space, as well as Qt 4.1.1 or higher. If you really want to create, those numbers should probably be higher. I have found that a processor that is faster than 1GHz with at least 512MB of RAM does well.
With a recent release, you can now burn an ISO image of KToon to a CD for a portable live version of KToon that can be booted on any computer. This is a useful method for trying the program if you are not running Linux.
Ktoon is still in its early stages, so it is not the most functional piece of animation software there is yet, but it is excellent for simple animations. It has the beginnings of great tools for animation, such as the ability to create multiple brushes for complex animations, as well as the ability to create keyframes. These serve as tools for not only organization, but also as a means to help out in the animation process. Ktoon has a feature called "onion paper," in which the frame that is being modified can be transparent, allowing the animator to see the same general outline that the previous frame had, which in turn allows subtle changes between frames to be created with less time and effort. Most commands are easy to find and experiment with.
KToon also has its share of bugs that need to be ironed out. For instance, the recommended way to start the program requires opening a terminal window, getting to the directory where KToon is installed, and manually initiating it there. If KToon is not started in this manner, there is a possibility that you will not be able to save any of your work.
KToon comes with the ability to store to a .SWF file type, otherwise known as Flash. However, to do so, it really just exports the animation in bitmap format, frame by frame, which makes for a very large file. If this is changed in later versions, it might make the program more popular, since there are not many viable Flash alternatives in the Linux environment.
I have yet to have KToon crash on me, but other users of the program have lost work due to program crashes. Save your work frequently.
The advantages that KToon has to offer do outweigh its bugs, for the most part. It is an excellent tool for simple 2D animation, and it is easy enough to get into. The interface is intuitive enough that newcomers can pick it up and work it without too much trouble, and it is a pretty lightweight package.
KToon also has an informative documentation portal, with information relating to both use and development of the program. The information is presented in a variety of different languages, and includes tutorials on making your first animation, creating different themes for KToon, general tips, and frequently asked questions.
KToon is not without competition. The open source vector animation program Synfig is in an early stage too. It takes after the animation studio formerly known as Moho, now known as Anime Studio. There is also the program known as Plastic Animation Paper; however, it is not free. KToon may see a bit more of a faster development cycle, due to its backing by Colciencias, the Colombian institute for the Development of Science and Technology, as well as ParqueSoft, a technological organization that gives backing to startup technology groups.
KToon is free software under the GPL. While today it runs only on Linux, the developers have stated that they will develop versions for Windows and Mac OS X in the future. The community behind KToon is helpful. You can find discussion boards as well as fairly helpful tutorials and support, such as frequently asked questions and mailing lists, on the project's home page.