Let's call this one "An exercise in getting the real facts." Many of the arguments against FOSS software out there are just plain wrong, and having a few links ready to educate the uninformed at least gives others a chance to get their facts straight .
Take Gimp, for instance. Gimp released again, and like a Holiday on the calendar, that always means it's flame-weekend on the Internet. Gimp is proprietary software users' number-one favorite straw man. I have never seen the FOSS program that takes half the abuse that Gimp does.
Herein, some anti-FUD for the anti-Gimps, listed with false claim first and link to prove it wrong afterwards:
"Gimp doesn't have CMYK support."
"Gimp doesn't have layer support."
"You can't do digital prepress with Gimp."
"Gimp can't even draw a straight line."
"Gimp doesn't have 32-bit support."
NOTE: Cinepaint is spun off from Gimp. Try them both, you'll see the relation.
Update: The maintainer of the Cinepaint site is really irked at me for this claim - see comments below. Nevertheless, when people tell you they don't use Gimp because it doesn't support 32-bit, your natural inclination would be to say "Have you tried Cinepaint"? I don't know what else I'm supposed to recommend.
"Gimp is intended to replace Adobe Photoshop."
Note the very bottom of the page: "What Gimp is not".
"Linux will never be used professionally for graphics."
UPDATE 5/12/07: A new article...
...has this to say...
"Linux is the default operating [system] on desktops and servers at major animation and visual effects studios, with maybe 98 percent [or more] penetration," CinePaint Project Manager Robin Rowe told LinuxInsider. "With the big dogs, there's nobody left to convert to Linux. Every studio is already on board."
"OK, wise guy, but they aren't using Gimp itself!"
Cinepaint originally had the name "Film Gimp". In the article, "ILM" stands for "Industrial Light and Magic"
"Gimp's interface is too alien."
Gimpshop is another Gimp variant specifically made for Photoshop users; not that there could be any pleasing them.
"Photoshop graphics are superior."
Not always! And just think, these people were entering a contest.
"Gimp is so poorly documented."
Now, if legitimate complaints are made about Gimp, so be it. Every program out there will have some shortcomings, and the Gimp is no exception. That's why it's still being developed. But I am sick and fed up with seeing these same disgusting lies reprinted,; these are pure myths about the Gimp that haven't applied in five years and some of them never applied at all. I never want to see these lies again.
Further tips when dealing with an anti-Gimp zealot:
Be sure to ask them if they have any links to graphics they've done. Make this challenge again and again for each naysayer. If you do any kind of graphics work, whether professionally or for your own website or even as a hobby, you at least have some claim to knowing what you're talking about when it comes to graphics editors. You'd be amazed how many people who slam the Gimp do not. If you find yourself being flamed by somebody who doesn't even have their own user icon, no home site, no portfolio, no experience, and can't even point to a single graphic file they've ever produced, you may be assured that you're dealing with somebody who has no idea whatsoever what they are talking about. Note that you don't need to insist that they are Rembrandt, that's not the point. But I think discussions about usability of graphics programs should concern only those who ever, ever USE graphics programs. I don't know how I got that crazy notion...
Oh, by the way, if this same person criticizes your graphic work, don't let it get to you. Remember that it doesn't take much to beat nothing, and those who have nothing have no defense but to put down what you have.