StarkNet
StarkNet is a general purpose ZK-Rollup built using STARK cryptographic proof system. StarkNet uses the Cairo programming language both for its infrastructure and for writing StarkNet contracts
Foundations
Cairo
Cairo[1] is a programming language developed by StarkWare Industries (“StarkWare”) for writing provable programs, where one party can prove to another that a certain computation was executed correctly. Cairo and similar proof systems can be used to provide scalability to blockchains.[2]
GPS
Cairo’s Generic Proof Service (GPS). Will allow developers to build their own applications using Cairo, implementing whatever business logic they wish and send their Cairo code to the GPS to be proven, and then verified on-chain.
GPS enables a single proof to assert the integrity of execution of altogether separate and independent applications, thereby giving those applications the ability to amortize the gas expense of proof verification amongst them.
StarkEx
StarkEx StarkNet´s L2 scalability engine. It has been serving DeversiFi’s customers on Mainnet since June 2020. StarkEx can handle complex trading logic (spot trading, derivatives, NFTs) as well as payments.
StarkEx is a live example of the ability to scale applications using a STARK-based ZK-Rollup, and is the first application in production on Mainnet written in Cairo. As such, it will also be one of the applications running on StarkNet.[3]