As US Supreme Court agreed on Monday to give Microsoft a hearing related to a 2009 court order that required it to pay $290 million to i4i for patent infringement related to its high-profile product Microsoft Word, Microsoft itself has been on a buying spree collecting patents that cover a range of its products.

Also recently Novell's acquisition of Attachmate had raised questions about a deal component which included sale of 882 patents to a Microsoft led consortium which had raised concerns among FOSS community regarding the future of UNIX and OpenSUSE.

Microsoft's motivation in piling these patents has been a subject of much scrutiny. Some reports deem Microsoft's patent buying spree as a preemptive measure to protect itself from patent trolls and competitors. But others surmise that Microsoft could exercise intellectual property rights as assets on its balance sheet to generate revenues like patent trolls.

Usually companies the scale of Microsoft who are involved in using patents to develop products exercise patent rights to gain permanent injunction to protect their market share. Microsoft's lawsuit against Motorola and HTC could be an attempt to shield turf for its Windows Phone 7. Also the lawsuit was filed on Oct. 4, just days before Windows Phone 7 was released.

However, there are patent trolls like Acacia, from whom Microsoft recently bought patents, who do not seek to create products using patents but are more inclined to exercise IP rights to get license fees.

Microsoft has been involved in buying patents and signing cross-license deals with companies to build its portfolio of patents. While open-sources fear these developments and competitors go around buying patents in recourse Microsoft is sure brewing a storm in the world of patent wars.

Here is list of major patents acquisitions and cross-license deals signed by Microsoft in 2010:

CANESTA

Microsoft acquired Canesta, a 3-D image sensor chip-maker based in Silicon Valley in October. Canesta possesses 44 patents and has filed a few more with regard to electronic perception technology. Its technology is utilized in developing motion-sensing devices like Kinect.

ACACIA:

Microsoft licensed 74 patents from Acacia Research Corp. and Access Co. Ltd, a Japanese firm that had acquired PalmSource. The portfolios of patents are related to smartphone technologies and also included IP rights over technologies created by Palmsource.

Microsoft also licensed patents from Acacia related to technology for enhancing image resolution in May and in January had licensed patents from Acacia subsidiary related to software compilers.

AMAZON:

Microsoft and Amazon signed cross-license agreement that grants them access to each other's patent portfolio's which includes technologies related to Amazon's Kindle e-book and Linux servers.

Microsoft also has existing cross-licensing partnership deals with Apple, Samsung, LG, Xandros, Fuji-Xerox, NEC Corp., Seiko Epson Corp. and Toshiba Corp.

Microsoft Smartphone Court Samsung