my company is developing ASP.net projects and we want to find a general solution to use Piwik tracking in our projects with serverside code. On the piwik page I found the Piwik C# Tracking API solution a well done C# library implementing everything we need. But there is one problem: We need the request asynchronous and not synchronous. All our projects are commercial and the sourcecode isn’t free. The library is distributed under the GPL licence and if I want to change code I have to make my project GPL too, right? Is there a possibility to change code and do not open our project to everyone?