We introduce ProjectQ, an open source software effort for quantum computing.The first release features a compiler framework capable of targeting various types of hardware, a high-performance simulator with emulation capabilities, and compiler plug-ins for circuit drawing and resource estimation.We introduce our Python-embedded domain-specific language, present the Bowl (Set of 3) features, and provide example implementations for quantum algorithms.The framework allows testing of quantum algorithms through simulation and enables running them on actual quantum hardware using a back-end connecting to the IBM Quantum Experience cloud service.Through extension mechanisms, users can provide back-ends to further quantum hardware, and scientists working on quantum compilation can provide plug-ins for additional compilation, optimization, gate DVI-D Digital Video Cable synthesis, and layout strategies.