microsoft/Quantum-NC

Quantum-NC (hosting the Liquid platform) is a legacy project from Microsoft Research, now largely superseded by the open-source Q# and Azure Quantum Development Kit. While it holds historical significance and contains sophisticated simulation algorithms, its 'Non-Commercial' license and 3000-day age make it a poor candidate for modern development. The defensibility score of 5 reflects the depth of the original research and the difficulty of recreating specific high-performance simulators from scratch, but the project has no forward momentum (0 velocity). It has been displaced by modern ecosystems like IBM's Qiskit and Google's Cirq, which offer better integration with Python and cloud-based hardware. Frontier labs (OpenAI, Anthropic) are unlikely to engage with this niche, as their focus remains on LLMs and classical compute, leaving quantum software to specialized hardware providers. The displacement horizon is '6 months' because the replacement technology (Q#) has already been available for years.