How i see it, quake 3 will always be quake 3, but I have long uninstall the game and see little reason to reinstall it. Especially with quake 4 out. Open arena is newer, and free, and incomplete (meaning it can only get better), "to tell you the truth i think open arena has more options to its seven year old parent".
In truth though, you shouldn't compare the 2.
I personally played will play open arena over quake 3 because i do not feel like digging through my pile of old video games.
Playing maps should be as easy as moving them over to your open arena folder "in a pk3 file", and since you own the game, it wouldn't be illegal to do so, however, it would be to play over the internet "I'm not sure, but I do recall that from memory somewhere".
The textures and sounds that are missing can also be solved the same way, you just have to know where they are. Which should not be that big of an issue.... i think. I know it worked for jedi outcast to jedi academy
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