Comics
A non-canon comic book series written by Frank Miller called RoboCop versus The Terminator suggests that the creation of Skynet and the Terminators was made possible due to the technology used to create RoboCop. A video game based on the comic book was made. In both, RoboCop fights Terminators sent back in time to eliminate a resistance fighter who is trying to destroy him. A trap laid for RoboCop traps his mind when he interfaces with the computer that will become Skynet, and Skynet and the Terminators are born. In the future RoboCop's mind within Skynet's systems rebuilds a body for himself and heads out to help the resistance fight back.
Another crossover comic, Superman vs. the Terminator: Death to the Future sees Skynet forming a cross-temporal alliance with Superman's foe the Cyborg, dispatching various Terminators into the past in an attempt to eliminate Superman, Supergirl and Superboy. When Superman is accidentally drawn into the future when the resistance attempt to retrieve a Terminator sent into the past- the resistance including a future version of his friend Steel-, Skynet manages to incapacitate him using kryptonite, having acquired information about how to duplicate it based on data hidden in a salvaged Terminator skull by the Cyborg. Although Skynet sends Terminators into the past equipped with rockets and other bonus features to delay Superboy and Supergirl, Superman and Steel are able to destroy Skynet in the future by detonating a massive electro-magnetic pulse, Superman returning to the past to destroy the last of the Terminators. Although the storyline ends with Cyborg and Lex Luthor speculating that they will be in charge of Skynet when it is activated, this is never followed up.
Read more about this topic: Skynet (Terminator)