WEBCAT от Freedom of the Press Foundation

Warning: This is experimental software and currently released as an alpha. It might slow down or interfere with web pages, and it might not yet provide the intended security guarantees.

WEBCAT verifies the provenance and integrity of web applications directly in your browser.
For the extension to be effective, a website owner must configure their domain and application to work with WEBCAT.

The extension does not affect websites that are not enrolled in the system and does not interfere with normal browsing. Protection is active only when a green icon appears in the top-right corner of the address bar. If an enrolled website fails validation, its content is blocked and a clear error page is displayed.

WEBCAT is currently experimental, and users are encouraged to report any issues.

Resources:

• User Guide
• Website Administrators & Developers Guide
• Source Code