I have been using Lazarus from SVN for well over year, on win32. It does feel stable and bugfree for me at least. I don't remember when it would have crashed or done something weird last time... must be many many months ago. If you constantly keep running and crashing your app though, expect bad things to happen some point Debugger is 3rd party software, not in any way modified by Lazarus team. But still, it should be able to handle alot of SIGSEGV's.