I've been doing quite a bit of searching, but I'm only turning up commercially licensed packages. I don't need something as fully-featured as Photoshop, but something in that genre is sufficient. These features are of most importance to me:
- Basic photo editing
- Some filters
- Layering
- Text tool
I want to be able to make simple posters/flyers by combining multiple images and text.
Best Answer
GIMP is widely recognised as a quality free alternative to Photoshop in many regards.
...but it's not considered to be particularly successful in it's approach to embracing Mac OS X application design ;)
If you want something that isn't necessarily free but is at least inexpensive, then there are a number of other programs including Acorn and Pixelmator available in the Mac App Store. You could always try the cut down Photoshop Elements.
For a good roundup, see this wonderful blog post from the Ask Different Community Blog for more info:
GIMP vs Photoshop vs Pixelmator – Graphics Editor Shootout