Honest to gods, this conversation happened today, and it may have cost me a job opportunity. The customer was super impressed with my menu design and animation, and wanted to know who we got it from. When I said I did it, their face lit up! Too bad as soon as i said GIMP, they weren't interested anymore. Has anyone else experienced this? What do you say in similar situations?
If you're pressed further just use its long name GNU image manipulator. It's a unique name and every search engine will turn up the correct website for gimp when you search it. Or you could just use the letters. "I used Gee Eye Em Pee"
Using the long name (it's actually GNU Image Manipulation Program) is a good idea, but I have never actually had anyone press for the actual name Not giving the name also means I don't have to explain anything if I later used Inkscape or something else as those would also more or less fit the description I gave.