Options for developing an IDE

Thinking about doing my first IDE toy project. What is the most common approach for this today? Electron? Some sort of js/wasm? I need something with drag and drop functionality. Similar to the requirements in visually building an electronics circuit. Similar to MIT's Scratch. It doesn't matter if it needs to be installed, but I would prefer to run it in the browser—no preferences for any language in particular.

Any pointers would be much appreciated!