how to get blitzmax to work on mac

I can open blitzmax and everything but when i try to compile the code it doesn't work....ever. it works on pc not mac. is there something i have to download. This happens on all of the macs i have tried

I think you have to install xcode..?

According to the BlitzMax product page on this site:

MacOS Requirements: MacOS X 10.3.9 or higher; Project Builder or X-Code developer tools installed.

Yep. A compatible Xcode installation is your (mandatory) friend.