Qwik
Misko Hevery (the Angular creator) framework that replaces hydration with "resumability" — the app "wakes" from server state without re-executing components.
Builder.io, 2021. The idea: only the JS directly relevant to a user interaction is loaded — first-load is near-zero JS regardless of app size. Astro Islands is related but more manual; Qwik does automatic fine-grained code splitting at the function level.
Smaller community than React/Next, but interesting technical angle. QwikCity is its full-stack meta-framework. Competitor: Solid (same fine-grained reactivity), Astro (more content-focused).