Update README.md

README.md

@@ -7,9 +7,9 @@
 ### Boo
 
 **Boo** is a cross-platform windowing and event manager similar to
-SDL and SFML, with additional 3D rendering functionality. 
+SDL or SFML, with additional 3D rendering functionality. 
 
-The exclusive focus of Boo is 2D/3D rendering using polygon-rasterization
+The primary focus of Boo is 2D/3D rendering using polygon-rasterization
 APIs like OpenGL or Direct3D. It exposes a unified command-queue API for 
 calling the underlying graphics API.
 
@@ -17,15 +17,25 @@ The only per-platform responsibility of the client code is providing the
 shaders' source. Drawing, resource-management and state-switching are
 performed using the unified API; these may be written once for all platforms.
 
+Boo also features a unified audio API for mixing voices and performing variable 
+sample-rate-conversion. All audio computation occurs on the CPU, 'pumped' 
+by the client each frame-iteration.
+
 Client code is entered via the `appMain` method supplied in a callback object.
 This code executes on a dedicated thread with graphics command context available.
 The API may be used to synchronize loops on the client thread with the display
 refresh-rate.
 
-#### Supported Backends
+#### Supported Graphics Backends
 
 * OpenGL 3.3+
 * Direct3D 11/12
 * Metal 1.1 (OS X 10.11 only for now, iOS coming soon)
 * **[Coming soon]** OpenGL ES 3.0
 * **[Coming soon]** Vulkan
+
+#### Supported Audio Backends
+
+* **[Windows]** WASAPI
+* **[OS X]** Audio Queue Services
+* **[Linux]** ALSA