Paul_KY, stay cool ...this is one of the biggest Open Source project, is also included in any Linux release. If you trust ADOBE you can trust GIMP too. I have tried, and many others and e can't say nothing bad about.
You can take a look at the site: gimp.org
Let us know impressions if you will try, actually I wait feedback from anyone who try GIMP

Post your opinions guys.
Ovi