Your single-user license can be installed on up to two machines, for example, you can install your program on both a desktop and a laptop, or on a Mac and Windows machine.
This is a valid use of your license as long as you are the only user and are not using both computers at the same time. For more details, see our End User License Agreement:
You can transfer your license from one user to another (or one computer to another) by uninstalling on the old computer and reinstalling on the new computer using the same software key. See this support article.
Camtasia software keys will work on both Mac and Windows for versions of Camtasia 9 and later.