I know I certainly cannot afford to purchase any software for my students - and not 24-28 copies of it! So I did some looking on Google and I ran across somebody mentioning a piece of software called "GIMP".
Now, the name made me hesitate for a moment, as all I could think of was the guy all dressed in leather and chained in a box in Pulp Fiction. Thankfully, that has NOTHING to do with this software.
GIMP is open source software - for FREE (I love that word) and the name is an acronym for GNU Image Manipulation Program. So I just downloaded and installed the newest release and it totally knocked my socks off. I figured it would be something along the lines of Picasa - a basic adjust the brightness and you're done type of thing. Not hardly!
This program has layers, cloning brushes, color adjustments, handles image color profiles, text tools and even unsharp mask. Now, as I said, I just downloaded this and have only played with it for about 20 minutes, but for anybody that needs some serious editing power - on a budget - this is the way to go.
Yes, the tools/icons and menus are very different looking from Photoshop CS3, but once you find where things are (like brightness/contrast tool is in the color section) it is easy enough to use.
I am soooooo glad I found this, and I actually have time to learn it before schooll starts.
Now to explore the wavelet plug-ins, including one that is supposed to handle RAW files (and possibly .DNG???)