Well, almost :-) As of October 22nd we expect it will be. A lot of open-source projects release whenever suitable (which is perfectly ok) but the Electron development team has stated they intend to release consistently every 12 weeks (so a release every alternate Chromium version). Check out the release timeline. As Electron is a developer platform and has a lot of dependency on Chromium, that makes sense, and that time-frame can be pretty useful. If you were targeting to release an Electron app in early 2020, you can figure that there'd be at least a few minor bugfix versions released yet a few months available for developing on a stable version if you started now.
What is Electron?
In a nutshell, Electron takes the Chromium (ala Chrome) browser framework, adds in Node.js and allows you to use web development libraries (e.g. React) to build a desktop application. So that web thing you've written can be packaged as a desktop app. It's pretty trippy when you write a bit of code and then pull it from a repo and run it on Windows, then Mac and then Linux! But it's not quite that simple. There are subtle differences in each platform - the most obvious being menu differences - Windows has a menu per window, Mac has its omnimenu. So invariably there will be a bit of code for platform checking for menus, toolbars, the dock, tray, etc. Conceivably you could write a no-menu windowed web-app but it probably wouldn't feel very native to the OS. So there is likely time required to determine how to structure, build, and package your application for each OS. Still, as a web developer, it means you can start thinking about all those webby ideas in the context of a desktop app as well.
If you've read the threads at Hacker News, you've probably seen that in the past whenever Electron is mentioned there's a lot of negativity. Most of it directed at Slack's desktop application. But, they've fixed the memory-hungry beast that was their desktop app.
And Visual Studio Code which StackOverFlow reported as the editor used by over 50% of respondents(!) in 2019 is based on Electron. Visual Studio Code is a very capable editor and a great testament to what can be done on the Electron platform.
The Electron Architecture
Electron's architecture is, as you would expect, similar to Chromium. There is essentially the main process and a render process per window. Chromium has a process for each tab. In Electron, it's similar. Each render process runs your usual HTML/CSS/Javascript in its window.
The main process creates each render process (a new BrowserWindow object) and the main environment seems pretty similar to a NodeJS application. It used to be that a render process also had access to the NodeJS API (so you could use and in the same Javascript!) but by default, that doesn't occur anymore. There seems to have been a general shift to making the render process very UI-explicit and sometimes even keeping state elsewhere - so akin to having a hierarchy of presentation components that simply render UI, passing messages back to the state.
