Complex sentence: It was founded in 2004 by Srđa Popović and the CEO of Orion Telecom, Slobodan Đinović, former members of the Serbian youth resistance movement, Otpor!, which played a key role in the overthrow of Slobodan Milošević in October 2000.
Split into simpler sentences: It was founded in 2004 by Srđa Popović and the CEO of Orion Telecom, Slobodan Đinović. Both were former members of the Serbian youth resistance movement, Otpor!, which supported the overthrow of Slobodan Milošević in October 2000.