Cirq is a Python library for writing, manipulating, and optimizing quantum circuits and running them against quantum computers and simulators.
There are different quantum computing languages, frameworks and toolkits with various programming styles and target audiences. However, for the first generation of quantum computers, Google Cirq may be the most NISQ-focused from the available toolkits. Cirq is more of a low level frameworks: it allows physicists and computer scientists to control how their computation will be executed, and to specifically adapt it to the capabilities and limitations of each architecture. Cirq will be the interface to the Google cloud machine.