Apple loops are essentially audio files with meta data attached that tells Logic & GB what to do with them at certain tempos and keys.
Apple loops from Logic 7 and before are aiff files that should work as standard audio files in any sequencer, Mac or PC. However, the time stretching abilities won't be available unless you use GB, STP or Logic.
Also, note, Logic 8's apple loops are in the new .CAF (core audio format) file type, that to the best of my knowledge, are not supported by any other non-Apple app yet (mac or PC).
You can check the type of apple loops on your system here: