Orb is a free and open source web desktop, which simulates a Windows-like desktop in a web browser. You can use it to access files on a server or a NAS in an easy and secure way. (by hsleisink)
I took a peek at the "Explorer" app code base. PHP + JS + jQuery, but surprisingly readable (but a lot of practices in there that are not exactly considered "best" today). Perhaps we have sunk too deep into the SPA/API rabbit hole that we can no longer appreciate simplicity.
A macOS desktop clone built with TypeScript React, SASS and Framer Motion.
but it's not as extensible. I know GTK uses JS and CSS but I'm not talking about that.
I'm talking about something made purely in HTML + CSS + JS. Something like this: https://gianlucajahn.github.io/macOS-react/
If only these could support native Linux apps somehow (through a WM).
Appwrite - The open-source backend cloud platform. Add Auth, Databases, Functions, and Storage to your product and build any application at any scale while using your preferred coding languages and tools.
Modern VNC Server and client, web based and secure
Not exactly the same thing, but I had good experience with KasmVNC.
Despite having VNC in its name, it isn't fully compliant with the VNC protocol and doesn't support regular VNC clients. Instead, it exposes a web client that you can access to connect to the machine. It also felt surprisingly snappy and nice to use compared to my previous experiences with regular VNC.
Debian with i3 tiling window manager - Accessible in the browser using noVNC
Or have a real desktop without coding? 
Desktop environment in the browser
I love seeing more web desktops as I think it's an amazingly fun side project. It's interesting to me seeing how far people will go with these. I've been working on mine for several years now. Also open source if anyone is interested in checking it out.
Interactive graphical desktop environment for LiveG OS.
This is what I've been working on with LiveG OS, whose desktop environment, gShell, is written in HTML/CSS/JS: https://liveg.tech/os
The OS is also designed to run on mobile devices, so there's some cross-platform consistency between the system on desktop and mobile devices.
It's currently designed to run web apps, but the hope is to also include support for typical Linux GTK and Qt apps (or any app that uses Xwindows) soon to aid daily driveability.
The current release can't do much yet, but we'll be releasing our next Alpha version in about a week or two which include a few more useful features on top of what's already available on our site!
Unpopular Opinion: Desktop GUI is the most efficient and fulfilling way of Human-Computer Interaction
1 project | /r/programming | 19 Nov 2023
Show HN: ExaequOS, a new OS running in a web browser
2 projects | news.ycombinator.com | 16 Sep 2023
DaedalOS – Desktop Environment in the Browser
1 project | news.ycombinator.com | 29 Jul 2023
1 project | news.ycombinator.com | 19 Jul 2023
Show me your portfolios
4 projects | /r/webdev | 7 Jun 2023