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Phala is a trustless computing cloud whose miner nodes are all Secure Workers using secure enclaves. With this, individual developers can rent their own off-chain workers from Phala blockchain and enjoy the benefits. Fat Contract is meant to be written with Parity’s ink, except for the extensions we provide for Fat Contract. The key difference is where they are executed: the ink contract is executed by Substrate nodes and Fat Contract in pRuntime (runtime customed by Phala)