  Quantum computers are available to use over the cloud, but the recent
explosion of quantum software platforms can be overwhelming for those deciding
on which to use. In this paper, we provide a current picture of the rapidly
evolving quantum computing landscape by comparing four software
platforms---Forest (pyQuil), Qiskit, ProjectQ, and the Quantum Developer Kit
(Q\#)---that enable researchers to use real and simulated quantum devices. Our
analysis covers requirements and installation, language syntax through example
programs, library support, and quantum simulator capabilities for each
platform. For platforms that have quantum computer support, we compare
hardware, quantum assembly languages, and quantum compilers. We conclude by
covering features of each and briefly mentioning other quantum computing
software packages.
