At its core, Fresh is a routing framework and templating engine that renders pages as they are requested, on a server.Fresh Is Stable announcement, July 2022
Here's a good overview of the islands architecture:
Fresh uses preact and typescript (TSX) or JSX to render and template. That means that if you're already familiar with react-based frameworks, which are currently the most popular options in 2022, the learning curve for Fresh won't be that steep.
As many other frameworks tout the increasingly shorter build times, fresh simply doesn't have one.
Let's take a look at the general file structure and boilerplate of a Fresh project:
You can see that there is routing, general components, and more, similar to React. However, there's now a new islands folder. All components in this island's folder will be rendered client side, so that's where you throw the interactive aspects of your app.
Fresh takes care of automatically re-hydrating the island on the client if it encounters its use in a route's template.Fresh Is Stable announcement, July 2022
Fresh is ready to build production web apps and sites. It's lightweight and simple, but it can be used in many scenarios. We believe that the biggest issue with this new framework is the ecosystem size of Deno. However, this release may put Deno on the map, and make it ready for prime time. Deno in itself is a massive improvement when compared to NodeJS, it's just a lot newer and needs to be adopted first.