μTorrent, or uTorrent, is a proprietary adware BitTorrent client owned and developed by Rainberry, Inc. The "μ" in its name comes from the SI prefix "micro-", referring to the program's small memory footprint: the program was designed to use minimal computer resources while offering functionality comparable to larger BitTorrent clients such as Vuze or BitComet. μTorrent became controversial in 2015 when many users unknowingly accepted a default option during installation which also installed a cryptocurrency miner.