SDL-以电脑游戏为核心开发的多媒体库
SDL是Simple DirectMedia Layer（简易直控媒体层）的缩写。它是一个跨平台的多媒体库，以用于直接控制底层的多媒体硬件的接口。这些多媒体功能包括了音频、键盘和鼠标（事件）、游戏摇杆等。当然，最为重要的是提供了2D图形帧缓冲（framebuffer）的接口，以及为OpenGL与各种操作系统之间提供了统一的标准接口以实现3D图形。从这些属性我们可以看出，SDL基本上可以认为是为以电脑游戏为核心开发的多媒体库。
SDL支持主流的操作系统，包括Windows和Linux。在官方的介绍中，我们可以找到它所支持的其他平台。（SDL supports Linux, Windows, Windows CE, BeOS, MacOS, Mac OS X, FreeBSD, NetBSD, OpenBSD, BSD/OS, Solaris, IRIX, and QNX. ）。SDL本身从C语言开发，并且能很好的在C++等高级语言中使用。在官方可以看到SDL所支持的语言很多。（Including Ada, C#, Eiffel, Erlang, Euphoria, Guile, Haskell, Java, Lisp, Lua, ML, Objective C, Pascal, Perl, PHP, Pike, Pliant, Python, Ruby, Smalltalk, and Tcl. ）
SDL在GNU LGPL version 2下发布，这意味着你可以免费的使用。并且可以免费的用于商业软件的制作（只要你直接使用SDL的动态链接库，Windows下的SDL.dll）。如果你将SDL库编译进了自己的二进制代码中，你需要指明你所使用的SDL库的版本以及包括你自己修改的源代码，并说明这些代码的原始出处。这是很宽松的法律，你可以用如此强大的多媒体库完全合法的免费开发商业游戏。
Simple DirectMedia Layer is a cross-platform multimedia library designed to provide low level access to audio, keyboard, mouse, joystick, 3D hardware via OpenGL, and 2D video framebuffer. It is used by MPEG playback software, emulators, and many popular games, including the award winning Linux port of "Civilization: Call To Power."
SDL supports Linux, Windows, Windows CE, BeOS, MacOS, Mac OS X, FreeBSD, NetBSD, OpenBSD, BSD/OS, Solaris, IRIX, and QNX. The code contains support for AmigaOS, Dreamcast, Atari, AIX, OSF/Tru64, RISC OS, SymbianOS, and OS/2, but these are not officially supported.
SDL is written in C, but works with C++ natively, and has bindings to several other languages, including Ada, C#, D, Eiffel, Erlang, Euphoria, Guile, Haskell, Java, Lisp, Lua, ML, Objective C, Pascal, Perl, PHP, Pike, Pliant, Python, Ruby, Smalltalk, and Tcl.
SDL is distributed under GNU LGPL version 2. This license allows you to use SDL freely in commercial programs as long as you link with the dynamic library.
Welcome to the last planned release for SDL 1.2!
http://www.libsdl.org/download-1.2.php