Nate the greatest writes "Do you remember last month when the Hamstersoft ebook converter got a lot of publicity? It turns out that the app is actually built from code that was stolen from calibre, the ebook library app. One calibre contributor is now reporting that his code was pirated for Hamstersoft.
You can find the full details over on John Schember's blog. It's technically complicated and quite long. You can also find a non-technical summary here.
The short-short version is that Hamstersoft needs to give away a complete source code for the Hamstersoft Ebook Converter because that app uses parts of calibre, which is licensed under GPL v3. John gave Hamstersoft a month to comply and they did not. Now that app is clearly a GPL violation."
Link to Original Source