* [Private Captcha v1.45.0](https://github.com/PrivateCaptcha/PrivateCaptcha) – Independent, privacy-first, self-hostable Proof-of-Work CAPTCHA service built in the EU.

* [Cap standalone@3.1.13](https://github.com/tiagozip/cap) – Lightweight, modern CAPTCHA alternative using SHA-256 proof-of-work focused on privacy and ease of integration.