CIEL is an execution engine for distributed, parallel computation. Like previous frameworks (such as MapReduce and Dryad), it masks the complexity of distributed programming. Unlike those frameworks, it offers a full general-purpose programming language, called Skywriting, for expressing distributed coordination, which enables developers to implement algorithms using arbitrary task structures. For documentation, tutorials and examples, please visit: http://www.cl.cam.ac.uk/netos/ciel/