 The Quake engine was updated with a new executable titled QuakeWorld that contained code to enhance the networking capabilities of Quake in response to the demand for across-internet network games that arose as a result of "Quake"s usage of UDP for networking.It was later updated again for the release of "Quake II" in 1997, with enhancements such as colored lighting and a new MD2 model format.By way of "Half-Life", it was also adapted into the GoldSrc engine and its successors, the Source engine and Source 2.