[riquito]

It's been a while, and overall I'd like them to succeed, but here are the first issues I remember.

The fact that scoped elements are not yet part of the standard is quite a turn off. Every web component is global and the first one that uses a name wins. Even if you are not competing with third party libraries you will need to have multiple versions of your same component very soon to handle breaking changes.

The string only passing is an headache when you'd like to pass object/functions to compare later on.

The fact that some CSS properties can bleed in the shadow Dom, while others don't.

To introduce them into an existing codebase you need support, and last time I checked the support from React was clunky

[djbusby]

I've been able to piece-meal RiotJS components into an existing code base pretty easy.

Tools like React, etc al, requires almost doing everything that way.

RiotJS fits in for adding a bit to "old-school" web-apps (PHP, Ruby, Perl, ASP3).

Legacy backend, slightly more modern frontend.