http://valinet6l6tq6d5yohaa6gdsf2ho4qcqcxyj2nahp5kd4z7nsa6ycdqd.onion/2015/06/17/Why-am-I-leaving-the-Windows-Phone-platform-for-good-today.html
Each party though developed its own interface, which was not compatible with apps developed for some other interfaces. This way, interfaces like S60, Series 80, Series 90, ICQ, MOAP, OPP and others appeared, yet it was S60, which was backed by Nokia, which took most of the market, as Nokia was back then the leading phone manufacturer in the world.