There is also coder.com which provides more or less the same thing (running Visual Studio Code in the browser).
The code is actually open source and you can run it on your own machine: https://github.com/cdr/code-server
Hint: Set the following environment variables before starting code-server to get access to the official Visual Studio Code extension marketplace. This is against the TOS of VSCode, but some extensions are missing/broken on the alternative marketplaces.
SERVICE_URL=https://marketplace.visualstudio.com/_apis/public/gallery