I’ve just released an application that lets you write and test AppleScriptObjC code outside Xcode, with expanded logging, and also export AppleScriptObjC-based applications. It’s a great way to write and test code, and an excellent learning tool.
You can read about it and download it here:
http://www.macosxautomation.com/applescript/apps/explorer.html
It’s shareware, and it requires 10.6.