Impression Math Expression Parser

I just downloaded two versions of impression... The complete lack of any documentation or examples caused me to not use this project. In addition, there is no clear indication of what licence it is distributed under (the sourceforce project page says Apache Software Licence, which doesn't sound right).

If you want users, provide documentation. At the very least Javadoc comments, preferably some sort of user's guide or tutorial to show how the system should be used.