Merge pull request bevyengine#7 from alice-i-cecile/what-is-bevy

What is bevy

Author: theotherphil

content/learn/book/intro/what-is-bevy.md

@@ -6,8 +6,43 @@ weight = 1
 status = 'hidden'
 +++
 
-TODO:
-- A game engine
-- In Rust
-- ECS
-- Highly modular and configurable
+Bevy is a modern, ECS-first game engine written in Rust. We aim to be:
+
+- **Capable:** Offer a complete 2D and 3D feature set
+- **Simple:** Easy for newbies to pick up, but infinitely flexible for power users
+- **Modular:** Use only what you need. Replace what you don't like
+- **Fast:** App logic should run quickly, and when possible, in parallel
+- **Productive:** Changes should be visible quickly... waiting isn't fun
+
+Bevy is [MIT](https://github.com/bevyengine/bevy/blob/main/LICENSE-MIT) + [Apache v2](https://github.com/bevyengine/bevy/blob/main/LICENSE-APACHE) licensed and controlled by the [Bevy Foundation](httaps://bevyengine.org/foundation/), a 501c3 charity run by the maintainers who do the day-to-day work to make Bevy what it is.
+It's built in the open, powered by hundreds of [community contributors](https://bevyengine.org/learn/contribute/introduction) and funded by the [generous donations](https://bevyengine.org/donate/) of the hobbyists and businesses that love and rely on it.
+
+## Why use Bevy?
+
+Bevy is delightful! You should use Bevy if:
+
+- You like Rust: it's a modern, safe, high-performance language with incredible tooling and a welcoming community
+- You like ECS: it's fast, elegant, extremely parallelizable and handles extreme levels of complexity well
+- You prefer a code-first approach to game logic: it's all just plain Rust
+- You're making something unusual (like CAD software, an art installation, or a scientific simulation), and value Bevy's extreme flexibility
+- You care about open source and feel more comfortable when you can read/understand/hack your tools from top-to-bottom
+- You want an engine with a lively [community](/community/) of users, engine devs and ecosystem creators
+- You never want to have to pay licensing fees or worry about vendor lock-in
+
+## Why not use Bevy?
+
+We love Bevy, but it's not the right tool for every project. You should not use Bevy if:
+
+- You need a stable, mature tool
+  - Bevy iterates quickly, and ships breaking changes approximately once every four months
+  - Many serious users upgrade Bevy mid-project with the help of our [migration guides](https://bevyengine.org/learn/migration-guides/introduction/), but this can be a serious time sink on large projects
+- You want to ship (relatively traditional) games very quickly
+  - Bevy is still not finished, stable software: many important features are missing!
+  - While you can build these features yourself, or work with others in the community, doing so will take valuable development time and add risk
+  - [Godot](https://godotengine.org/) is a fantastic choice for many common game genres, and it's even [scriptable with Rust](https://github.com/godot-rust/gdext)!
+- You need to make a lot of game content: Bevy does not currently have a graphical editor
+- You want scripting language support out-of-the-box
+  - Unlike other game engines, gameplay logic is written in the same language (and style!) as engine logic
+  - That said, it is possible. Bevy and Rust make sure that users have the tools needed to integrate Lua, Python and more
+  - Take a look at [Bevy Assets](https://bevyengine.org/assets) to see the options that the community have provided
+- You want to ship to consoles: Rust, and therefore Bevy, is currently not supported on Sony, Nintendo, or Microsoft consoles