GitHub repo JuliusBrussee/caveman — a TypeScript Claude Code / Codex / Gemini / Cursor skill that asks the agent to talk like a caveman. 74,940 stars and 4,230 forks as of 2026-06-20, MIT, 15 releases (latest v1.9.0 on 2026-06-12). Project-published benchmark of 10 real Claude API prompts shows 65% average output-token reduction (range 22–87%); caveman-compress sub-skill cuts 46% of tokens from real memory files. The README's own Important box is the lead caveat: caveman only affects output tokens — thinking/reasoning tokens are untouched.
googleworkspace/cli (binary: gws) is a first-party Rust CLI for every Workspace API, built dynamically from the Google Discovery Service, with 95 skill directories, a Gemini CLI extension, and an opt-in Model Armor integration that sanitizes API responses for prompt injection. As of 2026-06-18 the repo has 27,134 stars, 1,426 forks, 31,992 weekly npm downloads, and 30 releases from v0.4.4 to v0.22.5 — all in March 2026, with no new release tag in 11 weeks.
Dietrich Gebert's ponytail hit v4.6.0 on 2026-06-15 with 17,921 GitHub stars, 761 forks, and 8 releases in four days. The ruleset teaches Claude Code, Codex, Gemini CLI, OpenCode, Cursor, Windsurf, Cline, Aider, Kiro, GitHub Copilot, and Pi agents to ask 'does this need to exist?' before they type — and ships with a reproducible promptfoo benchmark (median of 10 runs across Haiku, Sonnet, Opus) showing 80–94% less code, 47–77% lower cost, and 3–6× faster runs than a no-skill baseline. Five-task scope, MIT, every shortcut tagged for later.