Re: Difference between a port and another version of the software?
"Porting" is where you modify the software to make it run on a different operating system or different CPU architecture.
With open-source software, sometimes somebody other than the official author will port the software to a different operating system.
If there is an official port and an unofficial port, then choose whichever one seems to have more features, works better, or looks more "native". For example, Openoffice has an official OS X version, but there is also a port called NeoOffice. OO is more up-to-date, but NeoOffice looks more "native". Choose whichever one you prefer.
I hope my advice helps. Please let me know whether it did!