There are numerous players in the mobile and tablet market, though that number is starting to dwindle. Android and iOS are at the front of the pack, with Windows Mobile 8 and RT in third place, and then BlackBerry BB10. Gone is LG webOS (formerly Palm, then formerly HP) as it has traded hands again and is rumored to pop up in embedded systems and smart TVs.
Despite all of this, there are still organizations motivated enough to challenge the status quo: The Linux Foundation and the Tizen Association, which is a consortium comprised of Asian technology firms Samsung, Huawei, Fujitsu, NEC, and Panasonic; telecoms KT (Korea Telecom), SK Telecom, Orange, Vodafone, NTT docomo, and Sprint (now mostly owned by Japanese telecom SoftBank).
Read more at Tech Republic.