[Mike O'Brien]

Applications are just folders that Mac OS X recognizes as applications, right? Well, what's the magic?

I just got myself into a hole. I tried renaming an application, call it "App". I tried adding the version number to the application, so I renamed the application "App 2.0" (no quotes in the name of course). So far so good.

Then I changed my mind. I renamed the application back to "App". It turned into a folder. I couldn't run it any more.

I renamed it back to "App 2.0" and it morphed back into an application. I renamed it "App 2." and it turned into a folder. By experiment, I determined that as long as the name ended in a decimal point and a digit, it'd be an application. Anything else, and it was a folder.

What the heck is going on here and what can I do about it?

[Chuckit]

The primary way the system recognizes an application bundle is the .app extension. This is never visible in normal Finder browsing. Do a Get Info on the folder and make sure the name ends with .app.

[Mike O'Brien]

Dang it. I used to know that!

That did the trick. Thanks, Chuck.