Add the introduction to the Book

docs/src/introduction.md

@@ -1,2 +1,43 @@
-# Introduction
+# The Asterinas Book
 
+<p align="center">
+    <img src="images/logo_en.svg" alt="asterinas-logo" width="620"><br>
+</p>
+
+Welcome to the documentation for Asterinas, an innovative open-source project and community focused on developing cutting-edge Rust OS kernels.
+
+## Book Structure
+
+This book is divided into five distinct parts:
+
+#### [Part 1: Asterinas Kernel](kernel/)
+
+Explore the modern OS kernel at the heart of Asterinas. Designed to leverage the full potential of Rust, Asterinas Kernel provides a high-fidelity Linux ABI compatibility. This means it can seamlessly replace Linux, offering enhanced safety and security.
+
+#### [Part 2: Asterinas Framework](framework/)
+
+The Framework lays down a robust, minimalistic foundation essential for OS development. It's akin to Rust's `std` crate but crafted for the demands of _safe_ Rust OS development. Asterinas Kernel is built on this very Framework.
+
+#### [Part 3: Asterinas OSDK](osdk/guide/)
+
+The OSDK is a command-line tool, streamlining the workflow to create, build, test, and run Rust OS projects that are built upon Asterinas Framework. Developed specifically for OS developers, it extends Rust's Cargo tool to better suite their specific needs. OSDK is instrumental in the development of Asterinas Kernel.
+
+#### [Part 4: Contributing to Asterinas](to-contribute/)
+
+Asterinas is in its nascent stage and welcomes your contributions! This part provides guidance on how you can become an integral part of the Asterinas project.
+
+#### [Part 5: Requests for Comments (RFCs)](rfcs/)
+
+Significant decisions in Asterinas are made through a transparent RFC process. This part documents the rationale behind these decisions and how you can participate in this process.
+
+## Licensing
+
+Asterinas's source code and documentation primarily use the [Mozilla Public License (MPL), Version 2.0](https://github.com/asterinas/asterinas/blob/main/LICENSE-MPL). Select components are under more permissive licenses, detailed [here](https://github.com/asterinas/asterinas/blob/main/.licenserc.yaml).
+
+Our choice of the [weak-copyleft](https://www.tldrlegal.com/license/mozilla-public-license-2-0-mpl-2) MPL license reflects a strategic balance:
+
+1. **Commitment to open-source freedom**: We believe that OS kernels are a communal asset that should benefit humanity. The MPL ensures that any alterations to MPL-covered files remain open source, aligning with our vision. Additionally, we do not require contributors to sign a Contributor License Agreement (CLA), preserving their rights and preventing 
+
+2. **Accommodating proprietary modules**: Recognizing the evolving landscape where large corporations also contribute significantly to open-source, we accommodate the business need for proprietary kernel modules. Unlike GPL, the MPL permits the combination and linking of MPL-covered files with proprietary code.
+
+In conclusion, we believe the MPL is the best choice to foster a vibrant, robust, and inclusive open-source community around Asterinas.