I'd also add that I think Mac software is far more capable 
of running on various versions of the OS than Linux.  Forward compatibility 
seems to be the norm...I still have an app that I download back in the 
10.1 days that hasn't been updated since, and it still runs fine on 
10.6.4.  
 
Usually the only limitations are when the software depends 
on frameworks and capabilities introduced with a specific OS, and those tend to 
be the major releases (e.g., 10.5 or 10.6, but not 10.6.3 or 
10.6.4).
Yes, you definitely can.