Web Development - CGI Scripting Web development meant "CGI scripts" for several years. CGI scripts are regular programs, that are ran by a web server, get their input using environment variables, in a standard manner, and anything they write to the standard output, is sent back to the Web browser. CGI scripts are often written using scripting languages, because their execution speed is limited anyway, and scripting languages make it easier to write them, and less likely to introduce security holes.