# Welcome to Quantum Cloud Services Quantum Cloud Services (QCS) is Rigetti’s quantum-first cloud computing platform. With QCS, [our quantum processors (QPUs)](https://qcs.rigetti.com/qpus/) are tightly integrated with classical computing infrastructure and made available to you over the cloud. {% hint style="success" %} If you don't already have a QCS account, you can [request one](https://www.rigetti.com/get-quantum). See [how-to-use-rigetti-qpus](https://docs.rigetti.com/qcs/guides/how-to-use-rigetti-qpus "mention") for an overview of all the platforms on which Rigetti QPUs are available. {% endhint %} ## Quil SDK The Quil SDK is a set of software tools that allows you to write quantum programs in [Quil](https://docs.rigetti.com/qcs/guides/quil/quil), then compile and run them on a simulator, or on a real Quantum Processor via QCS. The SDK is comprised of the following: * [**pyQuil**](https://docs.rigetti.com/qcs/references/pyquil): A Python library for building and executing Quil programs * [**quilc**](https://docs.rigetti.com/qcs/references/quilc): An optimizing Quil compiler * [**QVM**](https://docs.rigetti.com/qcs/references/qvm): A quantum virtual machine (quantum computer simulator) When you're ready, continue on to learn how to start using QCS and the Forest SDK. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.rigetti.com/qcs/master.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.