Web frameworks
Working with a framework makes it much easier to build scalable and maintainable applications compared to building everything manually.
In Chapter 4, Twilio in the Real World, we use the Laravel (http://laravel.com) framework to build our conferencing app. Other PHP options include CodeIgniter (http://www.codeigniter.com) and CakePHP (http://cakephp.org), both of which have strong community support. It's worth experimenting with different frameworks to see which one you like best.
Here are some recommended frameworks to play with if you're not a PHP developer:
In Ruby, the de facto standard is Ruby on Rails (http://rubyonrails.org), which is a hugely popular framework with almost endless extensibility thanks to Ruby's vibrant gems ecosystem. It powers sites such as GitHub and Shopify.
If you'd prefer something more lightweight, Sinatra (http://www.sinatrarb.com) is the most popular choice.
In Python, Django (https://www.djangoproject.com) is the most popular option, focusing on...