- Append new HTML, modify existing content and styles.
- React to users actions.
- Send requests over the network to remote servers, download and upload files (AJAX).
- Remember the data locally with local storage.
- Run without compilers and external software (browser engine is enough).
- Directly execute software, read and write files from hard drive.
- Automatically use microphone or webcam (user will be asked about permissions).
- Grab pieces of information from any websites (some need valid headers, or has denied header-origin properties).