Disclaimer: This is not a fully functional tool. It was created in order to better understand the inner workings of modern computer algebra systems.
Known bugs: When simplifying the calculator will not collect like terms in that are added together. For example, x + x will not be simplified to 2x. Also, when displaying long results in typeset form, the end of the expression will be cropped. You can get twice as much horizontal space to work with if you turn the anti-aliasing feature off.