The site it's being heavely updated. For most of the times, the updated site will be at test-version.html
This this a fashion open-source project using puter.js for the AI models. As I heavely used Claude the site's gui is based on it
You can open the AI chat at AI-With-Puter or at the Puter.com project
Running from a local file may break Puter auth. Serve via python3 -m http.server and open http://localhost:8000, or just go to one of the listed link above.