I tried running a full desktop OS inside a browser tab, and it actually works for real work

Puter is a free, open-source project that replicates a full desktop OS experience inside a web browser tab. It includes a taskbar, file manager, app center, and built-in tools like OnlyOffice for documents and Photopea for image editing. The author tested it for real work tasks including writing and RAW photo editing, finding it surprisingly capable despite some quirks like file picker issues. Puter can also be self-hosted on a NAS, though the self-hosted version lacks app store support. While the practical use case is debatable, it's an impressive demonstration of what's possible in a browser.