basic picture editing software for Mac OS X [duplicate]

Possible Duplicate:
What is the best Paint-like program for Mac OS X?

I am using a MacBook Pro running Mac OS X 10.5. I am new to this development environment, and previously worked on Windows.

I want to do very basic image editing, like cut a portion of an image, add some text label to the image, circle some part of the image, etc. I am downloading acornfree from this Url, but when executing acornfree, it said the Mac OS I am using is not supported. Any ideas how to fix this issue or any other free image editing software to recommend (and could be used for my specific Mac OS platform)?

http://flyingmeat.com/acorn/acornfree.html

Thanks in advance

Acorn 2.3 requires Mac OS X 10.6. You can download an older version of Acorn which works on 10.4 or later.

However, I urge you to check out Pure Mac's Graphics section, which has a large list of editors to choose from. I've used Seashore myself a couple of times, but there might be something better on that list that suits you.