The help text associated with each low-level function is from the corresponding .h header file that comes with SDL. If you installed libSDL1.2-devel with RPM, you may find the API documentation in file:/usr/share/doc/libSDL1.2-devel-1.2.3/index.html Otherwise, the documentation is available at http://www.libsdl.org

The Tutorial section of the Lush manual contains a tutorial on how to write simple video games with Lush and SDL. Tutorial: Writing Games with Lush and SDL.

• The SDL libraries (libSDL1.2)
  
• The SDL development libraries and include files (libSDL1.2-devel)
  
• The SDL_image library (libSDL_image1.2-devel)
  
• The SDL_image development libraries and include files (libSDL_image1.2_devel)
  

Those are generally available as RPMs or APTs for most Linux distributions. Otherwise, you can download the latest version from http://www.libsdl.org

By default, Lush looks for the SDL .so libraries in "/usr/lib". It expects to find "libSDL-1.2.so.0" and "libSDL_image-1.2.so.0". If these libraries are installed someplace else on your system, you must edit packages/sdl/sdl-config.lsh.