Also, if you haven't checked out Beaker Browser now that it's nearing 1.0 - great things are happening. This hasn't been broadcast much - but Beaker now has a built-in editor pane and forking mechanism. It's the best shot I've seen at a 'view source' 2.0.
There's been some healthy competition lately forking and editing the default twitter/mastodon clone. (Which is here: hyper://a8e9bd0f4df60ed5246a1b1f53d51a1feaeb1315266f769ac218436f12fda830/ But forks of it are here: hyper://0e0d1685c3575cf1df94191e14b4ecf068c43bcefee787ffbbed3d1f4666cab4/ and here: hyper://b798b86cc282ae065697f36a2a07072bfa28e5fdfa1d9a8c6fac0f07ff7d6676/.) If you want to learn Javascript, this seems like an amazing way. (Kind of like jsfiddle but for actual apps.)