Startups often fail because of timing, not ideas. Startups.RIP is a wiki of 1,700+ YC startups that shut down or got acquired. Our AI research agent writes a detailed post-mortem (what they built, why they failed, what's changed since) and a rebuild playbook with implementation-ready technical specs you can drop straight into your AI coding agent. Every failed startup is a validated market with unfinished business. Shortcut the idea maze. Start with what almost worked.