Mac Mini

[macdude425]

In Mac OS X, it's .app; there isn't one in Mac OS 9.

 

[Qiranworms]

In Mac OS X, it's .app; there isn't one in Mac OS 9.

If you want to get technical, you aren't actually running the '.app'...the '.app' is actually a folder in every way, shape, and form. You can 'ls' one in bash, or open most file managers other than Finder and you can browse it. In the folder is a binary (the actual application) and all the files needed to run the program (and almost any program in any operating system needs files other than itself to run...for Windows users, think .dll's...)

The Finder is where having the .app tag changes things. Finder treats it differently than a normal folder. Seeing the .app extension, it automatically instead of opening the folder looks in it for the binary itself to run. This basically enables applications to be very clean in the filesystem. While each has its own folder to store all the data necessary to run the program, the average user never has to see or deal with it...and can deal with one file that essentially represents the program. Simplicity for most people, yet everything is there for the power users that want to mess with the configs and such. I like the logic of it.