cmux
cmux is an open-source macOS terminal that helps developers using Claude Code, Codex, and similar CLI agents produce more manageable multi-project coding sessions with contextual notifications.
Tool overview
Based on the available evidence, cmux looks like an early but credible tool: it has clear attention, some usability signals, but still limited public proof of adoption. Heat proof mainly comes from X praise/reposts and several Chinese roundup articles. That shows interest, not product maturity. Better usefulness proof comes from the official repo description plus tutorial-style and feature-breakdown articles, which are more useful for judging what it actually does and how hard it is to adopt.
In practice, cmux is not Claude Code itself, not a general IDE, and not simply a cross-platform tmux replacement. A better analogy is a native macOS terminal layer redesigned for AI coding agents. The repo and articles consistently point to vertical tabs, project-oriented sessions, notification highlighting, and contextual metadata such as working directory, Git branch, PR status, ports, and latest alerts. For people juggling many agents, that matters more than traditional horizontal-tab terminals.
On cost and effort, the evidence supports that it is open source and free. That comes from the official repo and community articles.