The founder of Microsoft Corporation (NASDAQ: MSFT)'s Hotmail web-based email service seems to be at it again. Sabeer Bhatia, Hotmail's founder, sold his company last decade to Microsoft for a cool $400 million. Hotmail went on to become the software giant's premiere web-based email service, which competes with Yahoo! Inc. (NASDAQ: YHOO)'s market-leading Yahoo! Mail and with Google, Inc.'s (NASDAQ: GOOG) Gmail product.

Bhatia apparently wants another swipe at Ole' Softie, and he's launching a company named InstaColl that is aimed at Microsoft's lucrative Office productivity software franchise. Outside of the Windows operating system franchise, Microsoft's Office product line is the company's second-largest producer of revenue. Google's Docs & Spreadsheets program that came to prominence this year was originally thought of as a direct threat to Microsoft's Office business, but it's lukewarm capabilities so far have proven to be anything but that.

Will InstaColl change the competitive landscape, then? Basically, InstaColl is a suite of online office productivity tools, which sounds an awfully lot like Google's Docs & Spreadsheets. InstaColl's "Live Documents" was designed to give customers the complete functionality offered by Microsoft's Word, Excel and PowerPoint software. And, the great news -- it's offered for free (just like Google's office applications). Live Documents offers offline access to documents (something Google is working on as well), which has been the Achille's Heel of the web-based Microsoft Office competition thus far. For InstaColl business users, the cost if $5 per month per user.

Not sure if Microsoft is worried here, but online document tools sure seem to be a hot area now -- and it will only become hotter with time.