My understanding is that it effectively killed FogBugz as the software aged.
This led them to build Trello though, so maybe not a bad outcome?
When I used fogbugz, I loved it. I'd take it every day of the week instead of jira.
Fogbugz just got outcompeted by JIRA imo, and without the cross compiling that allowed it to run on linux (instead of just windows server) it would have been dead long long before.