New version for Yosemite and Mavericks users

ASObjC Explorer 4 is a script editor built to take full advantage of AppleScript’s ability to call Cocoa methods. With AppleScriptObjC-based libraries available in Mavericks and Yosemite, and now direct access to AppleScriptObjC code in Yosemite, ASObjC Explorer 4 can help you write and debug your code more quickly, more effortlessly, and more efficiently. It also makes a great external editor for those developing in Xcode.

ASObjC Explorer lets you write your code, write separate testing code, step through your code, log what happened, and even add scripting terminology — all in one document window. When you have finished, you can use your document as a script or library, or export to your favorite format, including Mavericks-compatible applets with embedded script libraries.

Full details are here.