Atari ROM Checker
The purpose of the "Atari ROM Checker" is to analyze and identify Atari 8-bit operating system ROMs based on their size and check sums. It contains a database of all known shipped or prototypes Atari operating system ROMs. It is open source, written in pure Java and runs fine on Windows, Linux and Mac OS X. The download and documentation available here. The sources are available here here.
The download also contains a simple automatic ROM dumper in Atari BASIC that runs on all Atari 8-bit machines with BASIC. Just boot the "AtariROMDumper.atr" with BASIC enabled. It will create a 16k file "D1:OS.ROM" and an 8k file "D1:BASIC.ROM" you can analyze then.