Complex sentence: ES&S was one of the top four providers of voting equipment used in the November 2004 election; the other three were Diebold Election Systems, Sequoia Voting Systems and Hart InterCivic.
Split into simpler sentences: ES&S was one of the top four providers of voting equipment used in the November 2004 election. The other three were Diebold Election Systems, Sequoia Voting Systems and Hart InterCivic.