A web developer wants a browser tool that is independent of browser restrictions. Which should they avoid using?

A browser extension is a tool that is specifically designed to extend the functionality of web browsers. It operates within the constraints and security policies of the browser environment, which can limit its capabilities based on the specific browser's rules. Since the web developer desires a tool that is independent of browser restrictions, a browser extension would not meet that requirement, as it relies on the support and permissions granted by browsers.

In contrast, options like MongoDB, REST, and HTML5 are foundational technologies that do not inherently operate within the confines of a browser's restrictions. MongoDB is a NoSQL database that functions independently on the server side, and it isn't subject to browser limitations. REST is an architectural style for designing networked applications, facilitating data exchange across various platforms without being bound to a specific browser environment. HTML5 is a markup language used for structuring content on the web but can also operate independently of a browser’s specifics when delivered through various environments, such as mobile applications or server-side rendering.

Thus, the focus on avoiding browser extensions aligns with the web developer's need for tools that bypass the limitations imposed by specific browsers.