ActionReplay & GameShark have always been by Datel (GameShark has used a sub company name at times but the main company has always been datel and use the exact same code system) nowerdays they are both known as Action Replay Max, before the Max arrived it was GameShark in the US and Action Replay in EU countries
CodeBreaker & Xploder are also both by the same people though under different names, they are still the same cheat system
You can convert most codes between CodeBreaker and Action Replay/GameShark V2 it can be a bit tricky though with the Master Codes, but if the game already has a CodeBreaker code then you don't need to convert the Master code, just the main codes, best to convert to raw first on a code you have on both cheat systems (just gives you a starting point) they should be the same code when in raw format, after that you can get cracking converting those
You can get Omniconvert from
http://www.epforums.org/showthread.php?72999 the link also has a basic guide for converting codes aswell