So there may be some leaks on win/mac too.
I should hope not. I spent far too much time plugging them! :-p
Non-GUI related... The default GC will appear to "leak" a certain amount of memory, when you run an app for a short time. But in reality this is more like having a bin which fills up and is then freed at some point during GC collection.
If you run the app for a longer time, you'll see that memory usage levels off.
Otherwise, you might have circular references in your code, which cause objects you think should be GC'd, to hang around for ever. That is a memory leak in the proper sense.