EXS 24 Logic Sampler Users Group

Actually the ESX editor is built into Logic, and you CAN create sound
libraries for the EXSP24.

I picked up the Big Box and I've been transferring samples from my
hardware sampler to the EXSP24. 

And I expect to see an AU version soon. 

Under the Audio menu/ESX instrument editor , then you can map your
samples to your keyboard.

Once you have your samples in .aif or .wav format, organize your
samples in folders. Move the folders to the EXSamples folder, located
in the Sampler Instruments folder.

Check out the online help for more details