This module allows you to authenticate users with a browser-based password (HTTP Auth). You can restrict access to the site by role and choose to secure restricted pages or the entire site. This means the site will be inaccessible to search engines and other crawlers, but you can still allow access to certain users.

This module allows the site admin to create custom error pages for HTTP status codes 403 (access denied) and 404 (page not found), without the need to create nodes for each of them.

This module is no longer under active development and hasn't been updated beyond 4.5-era Drupal.

Manage which roles can view, edit, and/or delete nodes by content type (default) or on a per-node basis (overriding defaults on each node).

Access control for user roles based on taxonomy categories (vocabulary, terms).

Add challenge-response tests to user-facing forms on your site to protect against spambot submissions. Other CAPTCHA types are supported via additional modules.