A file with the extension .PX5 is a plug-in file for use with 'Paragons Poker Pal' utilty.

Poker Pal is a 'Poker' assistant, that analyses in-game information to predict best hands and winning odds, maximising a users chance of winning.

.PX5 files are additional plug-in's created to further enhance the usabilty of PokerPal. An example of a .PX5 plug-in is the file 'PotOddsProcessor.px5'.