AlpineJS is possibly the easiest framework you'll ever learn. With just 15 attributes, 6 properties and 2 methods you'll be up and going without you knowing it.
Astro tries and succeeds at something different. It's a meta framework that lets you use one or more components from any other framework including React, Vue or Svelte with Advanced features like Hydration.
Pico CSS, The Exquisitely Classless Web Design Framework
CSS frameworks are awesome, but they can often be a pain to work with. The classes you have to write get complex quickly. The main concept behind Pico is to let you create as much content as possible with little or no classes.
SplideJS - Flexible and Accessible Carousel for Web Designers
This is a really cool library that gives you almost every option for creating different kinds of carousels. Touch enabled, has usability and accessibility features, pagination, vertical slides and really, just about any feature that I would want in a carousel.
Open Props Review: The CSS Variable Framework
One of the ways that some CSS frameworks are trying to make things easier is by giving you a set of pre-defined variables that can help you create a consistent look for your sites. Open Props offers a modular and extensible way to create designs based on these variables