There are some toy library programs out there, one off hand is Libratu - http://www.libratu.com/ http://www.libratu.com/ dog slow if you put a lot of data in it

There are some toy library programs out there, one off hand is Libratu - http://www.libratu.com/ http://www.libratu.com/ dog slow if you put a lot of data in it but may give you inspiration.