PortableApps and Linux.

Hi, this is not a question about running PortableApps in Linux.

The main question is the following: I'll maybe switch to a laptop with Linux, from what I read in some applications (Thunderbird, Firefox) it's only a question to copy a certain folder to the application structure so that the application can become portable. So, if I understand correctly, it does not matter if the folder is copied from Windows or Linux and so on. Is that right?

If the answer to above is yes. Which applications can not be made portable that way? Miranda IM comes to mind, but I don't know if there are others.

Thanx.