This library is designed to make it easy to write games that run on UNIX,
Win32 and BeOS using the various native high-performance media interfaces,
(for video, audio, etc) and presenting a single source-code level API to
your application. This is a fairly low level API, but using this, completely
portable applications can be written with a great deal of flexibility.
WWW: http://www.libsdl.org/
Use ${ECHO_CMD} instead of ${ECHO} where you mean the echo command; the ECHO
macro is set to "echo" by default, but it is set to "true" if make(1) is
invoked with the -s option while ECHO_CMD is always set to the echo command.
