lQuestion. I've been looking around online and haven't been able to come up with a solid answer to this. Maybe I'm just not understanding it all but I feel like I'm getting mixed answers as far as what I read. My girlfriend and I are working on a map on the current PS3 edition and I would like to transfer that map over to the computer server version 1.12 to work on there since we're more comfortable on the computer. Are the seeds compatible? I understand some things may not be the same which shouldn't be a big deal as long as it doesn't effect any redstone circuits.
Also I since the PS3 map is limited an the pc version is pretty infinite, will the map stay the same size or will it expand out?
(as far as I understand it, all but the java version are written in C++ or C# and almost all of those are cross compatible) The language it's written in has no effect on it's compatibility. If I really hated myself, I could write a compatible engine in QBasic...
The seed will "work", but it would probably generate a completely different map; you can easily test this if you like by putting the seed in a java version. Reading between the lines, I suspect you don't quite understand what you want. You would need to transfer the map, not the seed. I suspect that you might need a PS3->JAVA map converter but this is just a guess, a PS3 map might be the same format as an older version. A quick google search shows there are plenty of converters and tutorials on how to do this.
No matter what map you give JAVA version, it will continue generating "infinitely".
Short answer: google "PS3 minecraft map to PC" (without the quotes) and good luck!