We knew that rivals were already eying Google’s Project Glass eyewear, but a new patent application published recently reveals that Microsoft (MSFT) is among the companies developing heads-up display technology baked right into glasses. Unwired View on Thursday uncovered United States patent application 20120293548, which covers “a system and method to present a user wearing a head mounted display with supplemental information when viewing a live event.” Microsoft’s proposed tech would allow users to partially see through the lenses of a head-mounted display while “simultaneously receiving information on objects, including people, within the user’s field of view.” It is unclear if Microsoft is actively developing this technology in a product that might one day be commercially available.