Dao is a oopl featuring, optional typing, BNF-like macro system, regular expression, multidimensional numeric array, asynchronous function call for concurrent programming etc. Support for multi-threaded programming. Network programming and concurrent programming by MPI are supported as standard library. Dao can be easily extended with C/C++; and easily embedded into other C/C++ programs. Now the extending modules for Dao are gradually enriching, with modules for: CGI web programming, MYSQL database handling, Lapack and GSL numeric computing, GraphicsMagick image processing, MathGL mathematics plotting, OpenGL 3D graphics, SDL multimedia, XML docuemt handling and Zlib data compression etc. It worths mentioning that, most of these modules that wrap a C/C++ library are wrapped by an automated tool that written in Dao. module similar to the Ctypes module for Python. This module is based on the FFI library, and allows directly calling C functions without wrapping the library.