HN_htusers is a PHP class to manage users and groups in Apache Web server environments, with optional extra information for users. It uses Apache-style MD5-crypt passwords. It uses built-in CSS styles. Validation (min-max length, allowed characters) is built-in for all entries. The locking mechanism is robust. It includes examples of how to test your setup, how to embed a dynamic form for changing passwords into existing HTML code, using HTTP-Auth with .htaccess files in directories, and using HTTP-Auth without .htaccess files but with PHP.