I recently came across this situation when attempting to hack on Keepass2Android [0], a Keepass client for Android. It was written with Xamarin, which was a closed-source framework at the time. Having to download and use software with a 30-day trial to hack on an open-source project seemed wrong.
Now that the Xamarin SDK is open-source[1] it looks like it's moving towards being freed, which I think is a good thing. That said, I'm not sure the IDE is available on Linux yet, so I guess it's still relying on non-free software.
Now that the Xamarin SDK is open-source[1] it looks like it's moving towards being freed, which I think is a good thing. That said, I'm not sure the IDE is available on Linux yet, so I guess it's still relying on non-free software.
[0] https://keepass2android.codeplex.com/
[1] http://arstechnica.com/information-technology/2016/03/xamari...