Libraries
Android includes a set of C/C++ libraries used by various components of the Android system. These capabilities are exposed to developers through the Androidapplication framework. Some of the core libraries are listed below:
Surface Manager - manages access to the display subsystem and seamlessly composites 2D and 3D graphic layers from multiple applications
表面管理器——管理显示子系统，并能无缝地组合多个应用的2D和3D图像层。
3D libraries - an implementation based on OpenGL ES 1.0 APIs; the libraries use either hardware 3D acceleration (where available) or the included, highly optimized 3D software rasterizer
3D libraries——基于OpenGL ES 1.0 APIs的一个实现；该库或是使用硬件的3D加速，或是使用内置的高度优化的3D软件光栅。
SGL - the underlying 2D graphics engine SGL——底层的2D图像引擎
Media Libraries - based on PacketVideo's OpenCORE; the libraries support playback and recording of many popular audio and video formats, as well as static image files, including MPEG4, H.264, MP3, AAC, AMR, JPG, and PNG
媒体库——基于PacketVideo's OpenCORE；该库支持许多流行音频/视频的录制与回放，当然还支持静态的图片文件，包括 MPEG4, H.264, MP3, AAC, AMR, JPG, and PNG
FreeType - bitmap and vector font rendering FreeType —— 位图和矢量字体渲染
SSL：即Secure Socket Layer，位于TCP/IP协议与各种应用层协议之间，为数据通信提供安全支持。
SQLite - a powerful and lightweight relational database engine available to all applications
SQLite —— 一个强大而轻量的关系数据库引擎，对所有应用可用。
WebKit--浏览器排版和渲染引擎 具体介绍：http://www.infoq.com/cn/articles/webkit-for-developers
libc --系统c库