Compiling mandelbrot on Linux: You will need the devel files for the allegro graphics library. You should be able to find them via yum/zypper/apt-get or whatever the package manager of your distro is called. Of course you will also need GCC and the make command. If you have everything,just type "make" into a console and everything should compile in some seconds. Compiling mandelbrot on Windows: You need a C compiler. I prefer mingw32 (wxDevC++), but anyone should do. Then you have to get Allegro 4.2 for this compiler. If you are using (wx)DevC++, you can download a devpak file from devpaks.org. For other compilers: Google is your friend. Then you can compile mandelbrot (do not forget do tell the compiler / linker to include the allegro library!). NOTE: I do not know any compiler for Windows, which supports OpenMP, but perhaps a new MinGW version (not that old one from DevC++) or Microsoft's VisualC++ do, but I do not know. If your compiler does not like the "#pragma omp" lines, you have to remove them from the sources. Compiling mandelbrot on other Operating systems: I don't have any clue. You are on your own. Good luck!