I built some personal desktop apps with XUL(Runner) ~ a decade ago, it was fun to use web technologies (markup, JS, CSS, web browser view with relaxed security etc) to create a cross-platform executable. I have recently played with Electron and got the impression that it barely scratches the surface of what was possible back then but makes up for this thanks to the advancements in JS performance & ES6 syntax, CSS features (like flex, which was part of XUL) and the huge ecosystem of third party libraries.