said by DarkSithPro:Curious, are there any simple programs out there that can run on OS-X and Linux?
Binary compatibility is a separate issue, but much software written for Unix platforms will compile and run on OS X as well as Linux.
The same is not always true in reverse (Darwin or Linux specific functionality may not be present on other Unix and Unix-like operating systems).
As long as you consider shell scripts simple programs then it is definitely possible to write programs that will run unchanged on most Unix platforms (including OS-X and Linux).
