Even though I've jumped on the Chrome bandwagon, I still wear my blue Firefox golf shirt to work occasionally. Sometimes people ask me about it in the elevator. Sometimes these people are managers in our IT department. I've even had the same manager ask me more than once (given about six months between).
I want to know not just how would you respond to the manager, but how do you respond in general (kick the dog, curse, leave the company, indifference).
Elevator speech:
Firefox is an advanced web browser with all the features of Internet Explorer plus some additional features -- like ad blocking -- available as plugins. Many of the features in the newest Internet Explorer were copied from Firefox, and the next version of IE will likely copy more of them.
don't bore him with too many details, the bottom line is its improved performance (html rendering as well as javascript execution) and better security.
Tell them what it is. It's a web browser competitor to Internet Explorer, and viewed by many as the superior alternative.
Just tell them it's a web browser, presumably that won't work or they wouldn't be asking, so I'd say it's software kinda similar to Internet Explorer, but better (in your opinion).
Or ask him how he got his job as IT manager, but I assume you aren't in a position where you're comfortable enough to ask?
Well, you tell them the truth. You say it's a web browser which is generally regarded as more secure, more customizable and less bug-ridden then Internet Explorer. You tell them to visit getfirefox.com and give it a try.
You could be Nick Burnsy about it and act all snide about them not knowing what it is. But files, honey, vinegar, etc.
Maybe some day they'll also be asking you about this lye-nucks thing they keep reading about.
EDIT: Jeez, when I started writing this, there were zero answers. When I finished, mine was the ninth…
Tell him you borrowed your wife's shirt and you'll ask her when you see her tonight.
It's a Mach 6 Russian aircraft that the US government has asked you to steal. Ask him for his help in this venture.
Well, you'd have to pitch in the form of a progamming answer I suppose.
You know, because SO is supposed to be for programming questions, not nergasms about software.
Sometimes regular people ask questions in order to be polite or let the other person talk about something they care about. Even among IT folks, it's a bit nerdy to wear a shirt with a software product on it, so they might know what it is, but be curious why you care about it so much. You could say: "It's a web browser I like to use. Would you like to see it?"
You might as well get used to the fact that you care more about software than almost any random person, including other people who work on computers.
I think the point of the question is more to point out the ineptitude of his IT Managers and ask what people think about that.
As far as actually responding I would simply say that it is web browser with the second largest market share out there (as high as 25% depending on whos numbers you believe). You could briefly mention increased performance, security and it's high adoption rate among computer enthusiasts.
It is a bit troubling that your IT Manager hasn't gotten his feet wet enough in the field to know something as basic as what Firefox is. At the companies I have worked for the only path to becoming an IT Manager was to raise in the ranks from the IT field itself but I guess some companies don't mind hiring some suits with no experience.
Like Jeff says, in order to be a project or IT manager you need to know enough tech to know if the people you are managing are lieing to you (i.e. we are going to need two more weeks to make the flimflam work with the doohickie).
This reminds me of a UK based tv show "The IT Crowd". Here is a little quote from it's synopsis:
Jen, the newest member of the team, is hopelessly non-technical, despite claiming on her CV that she has "a lot of experience with computers". As Denholm, the company boss, is equally tech-illiterate, he's convinced by Jen's interview bluffing and appoints her head of the IT department. Her official title is "relationship manager", yet her attempts at bridging the gulf between the technicians and the business generally have the opposite effect, landing Jen in situations just as ludicrous as those of her team-mates.
"It's the web browser that's taking over from Internet Explorer"
Tell them politely that it is a good Web browser.
To the manager who asked you what it was again after six months, tell them politely that it is "still" a good Web browser. ;)