What is Astro?

What is Astro? And by that, I mean several things: what is Astro for? When is it a good idea to use Astro? And when is it not? What problem is it trying to solve? In other words: what is Astro's why… its "raison d'être" as the French would say?
Before we go any further, in order to research Astro and understand how it works, I actually rewrote my personal website with it, at kodaps.dev, using one of the templates Astro provides. Now, what is Astro ?
It might be easier to start by defining what Astro is not.
Astro is a JavaScript framework… but I hesitate to call it that. Why? Because people immediately assume that means a frontend framework. One intended as an alternative to React and the like. Astro is something else. It works with frontend frameworks, in collaboration not in competition with them.
It does not aim to compete with Next.js or Remix either, although those two do address similar use cases.
It's refreshing to hear Astro’s creators state that, no, they don't want to address every single need. And no, there are situations where Astro is not ideal for the job at hand.
Because Astro is … a tool. A tool that targets a particular use case: publishing content-focused websites.
What does that mean? Well, to understand that we'll be going over Astro's features, its strengths, and its weaknesses, such as:
- Astro's old-school page rendering model (and what use cases Astro targets)
- Astro's developer experience or DX
- Astro's "complexity you can opt-in to"
- How Astro goes about creating pages that load fast
- And the "islands of interactivity" model