I am mostly working under OSX and I am pretty happy with that. However, the work of porting my code to other OSes, which I need sometimes, is hindered by the lack of comfortable IDEs. I have tried the BloodshedDev IDE, which has been unsupported for quite some time, which doesn't matter so much, but it also feels too complicated. Same thing for KDevelop, a messy and complex solution. The FPC IDE is good as concept but clumsy.

Are there any others to consider? Remember, I want it simple and straight-forward, and I don't want any visual RAD tools so Delphi and Lazarus are beside the point. Maybe some other time, but now I want something simple and code-centered.