Internet Explorer 6 — long a thorn in the side of many web developers because of its quirks, limited feature support, and cockroach-like resistance to extinction —is finally on its last legs in the United States. And Microsoft is celebrating.

In a post on the Windows Team blog, Roger Capriotti, Director of Internet Explorer Marketing, writes that Internet Explorer is now down to less than 1% market share in the United States according to the most recent data from Net Applications. It’s far from the first country to reach that milestone — Austria, Poland, Sweden, Denmark, Finland, and Norway have done it already — but it also had far more Internet users to convert. Alongside the US, Microsoft also notes that the Czech Republic, Mexico, Ukraine, Portugal and the Philippines have all dipped below the 1% mark as well.

And while it might sound a bit odd to hear about Microsoft celebrating the demise of software it built long ago, this isn’t a change of heart for the tech giant — the company has been doing its part to help IE6 die for quite a while. It created the IE6 Countdown, which tracks the progress of countries worldwide as they work to move people to more modern browsers (Capriotti writes that the site has been visited by 2.75 million people and has drawn 5.6 million views). And when Denver-based design firm Aten Design Group held a funeral for the woefully out-dated browser back in 2010, Microsoft sent along some flowers.

Of course, while Microsoft would love for all of these former IE6 users to upgrade to the latest version of Internet Explorer, that doesn’t seem to be happening. Recent reports from StatCounter and NetMarketshare show IE trending downward — from 59.22% to 51.87% between February and December 2011, according to NetMarketshare — while Google’s Chrome is making steady gains (11.41% to 19.11%, in the same report).

More from Tech Crunch: