The big players (Gemini, Claude Code, Codex) and then aider and opencode for open source.
I keep my setup modular/composable so I can swap pieces and keep it usable by anyone (agent, human, time traveler) depending on what the task needs. In the aughts I standardized on "keep worklogs and notes on tools and refine them into runbooks" so that has translated pretty well to agentic skills/tools. (a man page is a perfectly cromulent skill, btw.)
I keep my setup modular/composable so I can swap pieces and keep it usable by anyone (agent, human, time traveler) depending on what the task needs. In the aughts I standardized on "keep worklogs and notes on tools and refine them into runbooks" so that has translated pretty well to agentic skills/tools. (a man page is a perfectly cromulent skill, btw.)