This page allows you to run elections using the Quota Preferential method of Proportional Representation. This is an excellent method of electing representative groups (eg, executive committees for associations). Of course we cannot guarantee that the implementation here is free of bugs and that the network is secure.
Before using your own data you might like to check out an example from the PRSA vote counting manual.
The system could be considered a prototype, though the output has been improved to provide reasonably detailed information about the progression of the count. You can look at the program (written in NU-Prolog) here, some additional documentation is here.