Microsoft this week rolled out a segundo prebiyu of its Internet Explorer 10 browser. Like the first, IE10 Platform prebiyu 2 is primarily intended to give Web developers and designers an early look at the upcoming features so they can prepare accordingly. Outside of a handful of demos, there isn't much for the average user to play around with -- it doesn't even ship with a url bar -- but it does reveal that Microsoft appears to be on the right track.

One of the madami talked about additions is support for the Web Worker API. What this does is give developers the freedom to throw multiple scripts at Web surfers to be executed simultaneously, allowing complex JavaScripts to run in the background. Traditionally, browsers have been single-threaded, and all it takes is one computationally intensive task to drag things down.

Other under-the-hood goodies include support for major platform features like HTML5 Parser, HTML5 Sandbox, HTML5 Forms, Media Query Listerners, and more. But perhaps most encouraging is Microsoft's focus on Web standards. We ran the segundo prebiyu through an HTML5 test at www.html5test.com and it scored 231 points out of 450, up from 141 in IE9. That's a nice improvement, though still behind the competition with Firefox 5 scoring 286 and Chrome 12 scoring 328.