Opera Software celebrates its 10th anniversary today with an online party and free registration codes for a day.

I first discovered the Opera web browser in college, probably 1998 or back in 1999. A friend who worked with me at the Artslab showed it to me, and I was impressed by how fast it was and that the installer fit on a floppy. Opera was shareware only back then, with a 30-day trial period, and I had no objection to paying the $15 or $20 $18 it cost with a student discount. (I remember scanning my student ID and emailing them a JPEG to prove I was a student.)

By the time Y2K rolled around, Netscape 4 was showing its age, and Mozilla was still early in its development cycle. IE—well, IE had won the browser war, and was arguably better than Netscape at this point, but as far as I was concerned they had cheated to do so instead of winning solely on merits. Opera was a lean, mean browsing machine.

Things changed during 2000, though. Opera 4 and 5 started getting cluttered, and Mozilla was starting to stabilize. Side projects like Galeon started branching off of Mozilla. Pretty soon I was using Mozilla all the time on Windows and Galeon on Linux.

I kept up with new releases, though, and the latest version of Opera is excellent—on both Windows and Linux. I mostly use Firefox these days, but I’m using Opera a lot more than I used to—and not just for testing!

Check out Opera, grab a free reg code while they’re still available, or just drop in on the party.

Seen in rounds at WaSP Buzz, Slashdot, and Opera Watch.

Also interesting: the Opera 10th Anniversary T-Shirt reminded me of Joi Ito’s comments on wearing Firefox (via a*dot). I wonder how people would react if I wore a Firefox shirt and an Opera hat, or vice-versa?

(Other notable tens this August: Windows 95 and Internet Explorer)