Our general policy is to assign all of our patents, whether homegrown or acquired, into Microsoft's name. However, in connection
with some acquisitions, there may be financial or legal reasons to maintain the patents in the name of the acquired subsidiary
(e.g., Skype). The
patent tracker tool
has been designed so as to make it possible to search for all patents for which Microsoft is the real
party in interest but are held in the name of a Microsoft subsidiary instead of Microsoft itself.