FunctionLab

Also available: DifferenceEqLab for difference equations.
To download the FunctionLab application to your computer, click here:
download FunctionLab.jar
or use ftp to access
ftp://www.myphysicslab.com/graphlab/build/FunctionLab.jar

By running locally on your computer, the copy buttons should work.

Documentation on the open-source code is available.