Cursor's Wilson Lin has been experimenting with scaling large fleets of autonomous coding agents, pushing the boundaries of AI-assisted programming. His team ran hundreds of concurrent agents on a single project, generating over a million lines of code and trillions of tokens. These agents used planners and sub-planners to create tasks, similar to how Claude Code employs sub-agents, with a judge agent determining project completion.

This ambitious project aimed to build a web browser from scratch, a challenging task that has become a benchmark for AI capabilities. The agents worked for nearly a week, producing a functional web browser with noticeable rendering glitches but legible pages. This achievement is remarkable, given the complexity of web browsers and the need for conformance to various standards.

The project, named FastRender, is available on GitHub, and recent updates include build instructions and the use of Git submodules to incorporate WhatWG and CSS-WG specifications. This approach ensures that the agents have access to essential reference materials. FastRender is the second AI-assisted browser project in recent weeks, following the HiWave browser, and demonstrates the rapid progress in AI-assisted coding.