The European Commission launched two formal antitrust investigations against Microsoft Corporation in relation to suspected abuses of dominance by refusing to provide interoperability information to competitors and tying Internet Explorer (Microsoft’s web browser application) to the Windows operating system. The investigations were triggered by complaints by the European Committee for Interoperable Systems (ECIS), and by Opera, a competing Internet browser vendor. Opera claims that competition in the sector is suffering considerable harm from Microsoft’s practices. In particular, Opera points to new proprietary technology in Internet Explorer that reduces compatibility with open Internet standards, and thus hinders competition.