Wow. An innocent question turns into a downvote madness here. Oh boy. So much hate...
What is up with the bull logo? what's the significance of it?
- c-graph, the guy must love trumpet
- classpathx, doesn't even look like a logo
- clisp, this looks like some icon from the 1990s website that I used to see a lot as a kid :)
- dejagnu, oh i know this. this was the lovely MS Office Word's Word Art! They generated from that. I used to make powerpoint and documents with word art when I was a kid.
- emms, this looks quite normal to me
- gcc, I never knew gcc has a logo
- gdb, fish as logo, what's the reason behind it?
- guix, wow, that looks like Chrome logo
- httptunnel, that looks like a tunnel to hell
- gnowsys, This one is little cute
- parallel, with a massive logo but I don't see anything resembles parallel. I am definitely not mathematician or geometry expert
- pspp, looks awesome. dat pie chart though
- a few don't actually have a logo, but a text logo
and finally
- wb, this is the most impressive one; looks like someone just crop something off a photo using photoshop.
But then again, neither I nor most people are designer and expectations of how a logo supposed to look might be quite different back then.