- a standalone app
- could create standard GUI elements
- had a decent library of packages which could be imported at need
I have been using:
https://www.blockscad3d.com/editor/
quite a lot (but it quit generating 3D previews of my projects a while back)
I'm hoping that:
will get to this point --- it seems promising enough I've been funding it since it was first announced.
Extensibility is a good point, and one that at some point I could implement. So far the block paradigm I've implemented only covers the primitive statements supported by Platypush' procedures (action, set, if, else, for, while, break, continue, return). But extensibility can definitely be a big win here - although extensibility means that the semantic of the new statement/block needs to be encoded both on the backend and the frontend (the frontend for example needs to know that I can't create a block after a return, or that break is only allowed within a loop).