of the bunch, closest to Photoshop in features. However, it has a UI that's way different than the Windows norm and confuses the heck out of a lot of people. You'll spend a bit of time just figuring out where everything is, but if you get past that, you'll be playing with a powerful program. Here's a peek at the Gimp:
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(Copy the URL after REMOVE to your address bar. I don't want to hotlink to this guy's pic)
Photoplus is kind of neat and its UI is modeled after Photoshop's. It's pretty good, kind of a Fisher Price version of PS, provides a small subset of the major features, enough to do decent webwork without having to deal with the minutiae of PS's deeper controls. However, it does have a few rough edges, an inattention to detail in the programming that can sometimes frustrate, like crops being cut a pixel or two outside of the area you lassoed (this may be fixed, my copy is over a year old).
Also, in order to download Photoplus, you'll need to register and provide an email address. Give them a throwaway address, unless you don't mind product pitches from a "Natasha Allchin" landing in your box a few times a week.
One more thing. Photoplus used to include an applet to check for updates. I don't like any sort of "phone home" junk, so if they're still doing that and they haven't changed their method -- look in the Program folder for a binary called WebCheck.exe. Rename it Webcheck.old. Open a blank page in a text editor and save it to the same folder as WebCheck.exe.
Screenshot of Photoplus:
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...and Photofiltre:
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