Adding to itimpi
Glance at the Download Page notes:
If there are any Special instructions or Limitations, they show there.
So Far (IIRC):
Windows version has only had 1 required special upgrade procedure, and THAT was years ago.
MAC has OS version limitations
Liniux has its requirements
Using: Ubuntu(32 bit):Oneric,Precise and XPpro SP3, W7HP(64)- - Libre Office w/Writer2EPUB