OpenAI vs Anthropic on Cyber AI Access, Nvidia Bets on Quantum, Anthropic Redesigns Claude Code

Today we’re covering the biggest AI stories of April 15th, 2026. OpenAI released GPT-5.4-Cyber with a deliberately open access model — anyone who passes an ID check can use it for defensive security work — taking a direct shot at Anthropic’s Mythos rollout which is locked to just 40 approved partners, framing the debate as “no one should be picking winners and losers” in cyber defense. Nvidia released Ising, the first family of open-source AI models built specifically for quantum computers — tackling calibration and error correction that have kept the technology stuck in labs, with Jensen Huang calling it “the operating system of quantum machines.” Plus, Anthropic redesigned Claude Code’s desktop app around the reality that developers now run multiple AI sessions simultaneously, adding a new session sidebar, drag-and-drop workspace, and scheduled routines — and a community workflow from a nearly 70-year-old who became the “AI Guy” at work by building a QR-based product tracking system using nothing but ChatGPT and Microsoft tools.