Ask HN: Know any Front-end heavy open source applications?

[nassimsoftware]

I want to build expertise in crafting Frontend heavy applications. One idea I had in mind was to look for open source projects to contribute to.

Any you would recommend? By Front-end heavy applications, I mean web code editors, web diagram tools, etc...

[themodelplumber]

Tiddlywiki comes to mind but IDK really how heavy it is. There are also editors like TinyMCE, CKEditor, etc.

[themerone]

Visual Studio Code