Bonjour on my wife's computer

My wife asked me a little bit ago to tell her what this icon in her IE toolbar called "bonjour" was. Neither of us had ever seen it before.
I had her do an uninstall, and I've done a google search and searched here, and really didn't find anything telling me where it came from.
I read that it's some sort of network detection, or something along those lines, but I'm curious where it came from.
She says she hasn't installed anything new, and I don't have it on my computer.
What can you tell me about this program?
Thanks a million.

 

Here's one I might have an answer for. Bonjour comes bundled with Kodak EasyShare software that you probably loaded for your camera. I found it on one of my computers. I believe it's harmless and can be un-installed.

 

Thanks, but she doesn't have the Kodak software installed.
On further grilling, I found out she has installed a Hallmark Card something or the other.
She's sitting over there cussing me right now because the software doesn't work right now. It doesn't seem to be able to find the photographs stored on our network now.
Thanks for the suggestion.