Intellectual Ventures is an invention development and patent holding company. It was originally founded in 2000 by Nathan Myhrvold and Edward Jung of Microsoft. The Wikipedia article about the company is here. The company's website is here.
Despite its impressive patent portfolio, up until today Intellectual Ventures never filed a lawsuit on its patents, preferring to license its patents. In some cases, it sold patents to other companies (some of whom filed lawsuits). However, today Intellectual Ventures filed three patent lawsuits, for the first time. An article about the lawsuits is here.
The lawsuits are Case Nos. 1:10cv1065, 1:10cv1066, and 1:10cv1067 in the U.S. District Court for the District of Delaware.