Complex sentence: The first popular jailbreak that included Cydia was Blackra1n, used for devices running up to iPhone OS 3.1.2; the currently used jailbreak is Limera1n, a newer version of Redsn0w.
Split into simpler sentences: The first popular jailbreak that included Cydia was Blackra1n, used for devices running up to iPhone OS 3.1.2. The currently used jailbreak is Limera1n, a newer version of Redsn0w.