Improve the README and switch URLs

1 files changed, 87 insertions, 14 deletions

diff --git a/README.md b/README.md
index a1c8fdeb90..88f6281363 100644
--- a/README.md
+++ b/README.md
@@ -4,21 +4,94 @@ libc
 A Rust library with native bindings to the types and functions commonly found on
 various systems, including libc.
 
-[![Build Status](https://travis-ci.org/alexcrichton/libc.svg?branch=master)](https://travis-ci.org/alexcrichton/libc)
-[![Build status](https://ci.appveyor.com/api/projects/status/v0414slj8y8nga0p?svg=true)](https://ci.appveyor.com/project/alexcrichton/libc)
+[![Build Status](https://travis-ci.org/rust-lang/libc.svg?branch=master)](https://travis-ci.org/rust-lang/libc)
+[![Build status](https://ci.appveyor.com/api/projects/status/v0414slj8y8nga0p?svg=true)](https://ci.appveyor.com/project/rust-lang/libc)
 
-[Documentation](http://alexcrichton.com/libc)
+[Documentation][#Platforms-and-Documentation]
 
-## Platform Support
+## Usage
+
+First, add the following to your `Cargo.toml`:
+
+```toml
+[dependencies]
+libc = "1.0"
+```
+
+Next, add this to your crate root:
+
+```rust
+extern crate libc;
+```
+
+## What is libc?
+
+The primary purpose of this crate is to provide all of the definitions necessary
+to easily interoperate with C code (or "C-like" code) on each of the platforms
+that Rust supports. This includes type definitions (e.g. `c_int`), constants
+(e.g. `EINVAL`) as well as function headers (e.g. `malloc`).
+
+This crate does not strive to have any form of compatibility across platforms,
+but rather it is simply a straight binding to the system libraries on the
+platform in question.
+
+## Public API
+
+This crate exports all underlying platform types, functions, and constants under
+the crate root, so all items are accessible as `libc::foo`. The types and values
+of all the exported APIs match the platform that libc is compiled for.
+
+## Adding an API
+
+Want to use an API which currently isn't bound in `libc`? It's quite easy to add
+one!
+
+The internal structure of this crate is designed to minimize the number of
+`#[cfg]` attributes in order to easily be able to add new items which apply
+to all platforms in the future. As a result, the crate is organized
+hierarchically based on platform. Each module has a number of `#[cfg]`'d
+children, but only one is ever actually compiled. Each module then reexports all
+the contents of its children.
+
+This means that for each platform that libc supports, the path from a
+leaf module to the root will contain all bindings for the platform in question.
+Consequently, this indicates where an API should be added! Adding an API at a
+particular level in the hierarchy means that it is supported on all the child
+platforms of that level. For example, when adding a Unix API it should be added
+to `src/unix/mod.rs`, but when adding a Linux-only API it should be added to
+`src/unix/notbsd/linux/mod.rs`.
+
+If you're not 100% sure at what level of the hierarchy an API should be added
+at, fear not! This crate has CI support which tests any binding against all
+platforms supported, so you'll see failures if an API is added at the wrong
+level or has different signatures across platforms.
+
+## Platforms and Documentation
+
+The following platforms are currently tested and have documentation available:
 
 Tested:
-  * `{i686,x86_64}-pc-windows-{msvc,gnu}`
-  *  `{i686,x86_64,mips,aarch64}-unknown-linux-gnu`
-  *  `x86_64-unknown-linux-musl`
-  *  `arm-unknown-linux-gnueabihf`
-  *  `arm-linux-androideabi`
-  *  `{i686,x86_64}-apple-{darwin,ios}`
-
-Untested:
-  * `{i686,x86_64}-unknown-freebsd`
-  * `x86_64-unknown-{bitrig,dragonfly,openbsd,netbsd}`
+  * [`i686-pc-windows-msvc`](https://doc.rust-lang.org/libc/i686-pc-windows-msvc/libc)
+  * [`x86_64-pc-windows-msvc`](https://doc.rust-lang.org/libc/x86_64-pc-windows-msvc/libc)
+  * [`i686-pc-windows-gnu`](https://doc.rust-lang.org/libc/i686-pc-windows-gnu/libc)
+  * [`x86_64-pc-windows-gnu`](https://doc.rust-lang.org/libc/x86_64-pc-windows-gnu/libc)
+  * [`i686-apple-darwin`](https://doc.rust-lang.org/libc/i686-apple-darwin/libc)
+  * [`x86_64-apple-darwin`](https://doc.rust-lang.org/libc/x86_64-apple-darwin/libc)
+  * [`i686-apple-ios`](https://doc.rust-lang.org/libc/i686-apple-ios/libc)
+  * [`x86_64-apple-ios`](https://doc.rust-lang.org/libc/x86_64-apple-ios/libc)
+  * [`i686-unknown-linux-gnu`](https://doc.rust-lang.org/libc/i686-unknown-linux-gnu/libc)
+  * [`x86_64-unknown-linux-gnu`](https://doc.rust-lang.org/libc/x86_64-unknown-linux-gnu/libc)
+  * [`x86_64-unknown-linux-musl`](https://doc.rust-lang.org/libc/x86_64-unknown-linux-musl/libc)
+  * [`aarch64-unknown-linux-gnu`](https://doc.rust-lang.org/libc/aarch64-unknown-linux-gnu/libc)
+  * [`mips-unknown-linux-gnu`](https://doc.rust-lang.org/libc/mips-unknown-linux-gnu/libc)
+  * [`arm-unknown-linux-gnueabihf`](https://doc.rust-lang.org/libc/arm-unknown-linux-gnueabihf/libc)
+  * [`arm-linux-androideabi`](https://doc.rust-lang.org/libc/arm-linux-androideabi/libc)
+
+The following may be supported, but are not guaranteed to always work:
+
+  * `x86_64-unknown-freebsd`
+  * `i686-unknown-freebsd`
+  * `x86_64-unknown-bitrig`
+  * `x86_64-unknown-dragonfly`
+  * `x86_64-unknown-openbsd`
+  * `x86_64-unknown-netbsd`