Why can't i run it on mac osx snow leopard

I’m trying to run the program on my macbook 1.1
running mac os x 10.6.8

when i try to open it i get a message telling me that
that the program can’t be run because it doesn’t support my mac

is there anyway to make it work
i’ve tried down to version 0.8.0

Hmm, you can try even older versions still available at SourceForge:

http://sourceforge.net/projects/tiled/files/tiled-qt/

There is no particular reason why Tiled no longer works on OS X 10.6, other than that I’m just compiling it with the latest version of Qt and Xcode on the latest version of OS X and this is what happens. You can try compiling it yourself with whatever version of Qt still works on OS X 10.6. I’m not sure which is the last one, but it needs to be at least Qt 4.7 for Tiled to compile with it.

Do i need xcode to compile(i already have xcode)
or do i just need Qt?

You need both, since the C++ compiler ships with Xcode.