The other thing, coming from windows, was not understanding where to install things. In windows there's like a single place where you install all your stuff.
/Users/behnam/Library/Application Support
which is _nasty_ when working in a terminal.MS tried to fix this by making directories like:
C:/Users/AppData/Local/I don't know why developers have apparently collectively decided to go backwards. If your software doesn't support spaces there's a reasonable chance it doesn't support more exotic characters either, which really sucks if you are not natively English speaking.