Kepler is a free software project written in Lua that provides a portable, extensible website development platform. Current stable release is Kepler 1.1.1, for Lua 5.1. Kepler works on Windows and most variants of Unix.The platform was designed to work with a number of web serving environments, called "launchers" in Kepler terminology. Kepler includes launchers for Apache (mod lua), FastCGI, CGI, ISAPI as well as a native web server written in pure Lua, called Xavante [1].