Firefox is a fine browser. Really, the current release of any of the major browsers is very good.

Firefox is currently, and comfortably, the #2 browser in market share. A look at the competitive landscape makes me wonder, however, if they have an audience in the long term.

There are probably two kinds of web users — those who make deliberate decisions about browsers and those who don’t. I think both will have less reason to use FF as time goes on.

Let’s look at the latter group. They want things to work, and work well. But they won’t see a real difference in usability between FF, IE, Safari or Chrome. I do and you do — but really, tabs and an address bar.

Sure, their friends or their kids might tell them it’s cool to use something other than IE, but unless those friends actually do the install for them, they won’t bother. They will stick with what their computer vendor gives them — and that means IE or Safari.

For those who care about their web browser, Firefox was the only non-bundled option in town. If you’re passionate about the web, or work in an IT department, Firefox is likely your browser of choice.

But now Google’s Chrome is on the scene, and many underestimate its potential impact.

It’s easy to say, well, now we have four contenders instead of three. Small change. But it’s more than that.

Chrome is the first real competition that FF has seen in the market that it largely created — that for true third-party browsers. There was no competition before. Now there is.

And Chrome has a lot going for it. It’s fast and stable (which is merely cost of entry). It’s got the backing of a major web company, with major resources and incentives to control the platform. It is the default browser on Google’s Android mobile operating system. (Keep in mind that a lot of Safari’s market share is attributable to the popularity of the iPhone. This is the growth market.)

Right now, FF has a very substantial and loyal user base. It’s not going away. I just wonder where its new users will be coming from. Either folks will go for the browser that came with their computer, or they will choose between Chrome and FF — and Google has the muscle.

So here’s my prediction: Firefox is near its peak in market share, and will begin to trend downward by the end of this year.

By this time in 2010, IE will have stabilized due to version 8 (and Windows 7). Safari will gain several percentage points in market share and Chrome usage will at least double from its current small base. That doesn’t leave much room for FF growth.

Update 17 May: added “growth” to clarify.