Python

$ python -m SimpleHTTPServer 8080

Replace 8080 with another number if you want it to listen on a different port.

For ports < 1024 it needs to run with root privileges.

The python 3.x equivalent of this is:

$ python3 -m http.server

PHP

$ php -S 0.0.0.0:8080

Ruby

Without gem

 $ ruby -run -e httpd . -p8080

With serve

 $ gem install serve
 $ serve 8080

Node.js

Use Connect and ServeStatic with Node.js:

  1. Install connect and serve-static with NPM

     $ npm install connect serve-static
    
  2. Create server.js file with this content:

     var connect = require('connect');
     var serveStatic = require('serve-static');
     connect().use(serveStatic(__dirname)).listen(8080, function(){
         console.log('Server running on 8080...');
     });
    
  3. Run with Node.js

     $ node server.js
    

Simplest Node.js server:

$ npm install http-server -g
$ http-server

Reference