ActivePresenter is a screencasting software that allows you to capture and publish what you did on your computer (similar to Camtasia).
The free version has some great features and export formats. It allows you to record your whole desktop, a specific window or a preset size window.
You can edit your recording afterwards using a timeline on the bottom of the screen to see ahead and behind the current view. You can insert things like annotations, voice overs, mouse clicks other videos and screenshots.
You can then export your project in different formats, including images, Video (AVI, WMV, MPEG4 and WebM) or Flash Video (FLV), PDF, Word, Excel, PowerPoint and a few other formats.
This is a great way for educators to produce tutorials, student help sessions and more.