An example of a Lua script being run under Apache mod_lua. From http://httpd.apache.org/docs/current/mod/mod_lua.html

apache.lua

require "string"

--[[
    http://httpd.apache.org/docs/current/mod/mod_lua.html
    This is the default method name for Lua handlers, see the optional
    function-name in the LuaMapHandler directive to choose a different
    entry point.
--]]
function handle(r)
    r.content_type = "text/plain"

    if r.method == 'GET' then
        r:puts("Hello Lua World!\n")
        for k, v in pairs( r:parseargs() ) do
            r:puts( string.format("%s: %s\n", k, v) )
        end
    elseif r.method == 'POST' then
        r:puts("Hello Lua World!\n")
        for k, v in pairs( r:parsebody() ) do
            r:puts( string.format("%s: %s\n", k, v) )
        end
    elseif r.method == 'PUT' then
        -- use our own Error contents
        r:puts("Unsupported HTTP method " .. r.method)
        r.status = 405
        return apache2.ok
    else
        -- use the ErrorDocument
        return 501
    end
    return apache2.OK
end