Server-side programming powers the client-side programming and is used to create the scripts that web applications use. Scripts can be written in multiple scripting languages such as Ruby, Java, and Python. Server-side scripting will create a custom interface for the end-user and hide the source code that makes up the interface.
Web applications will have a large amount of information that may contain mistakes, so the testing process for web applications tends to be more in-depth than other software forms. Web application development tests may include security, performance, load, stress, accessibility, usability, and quality assurance tests. Other tests that can be performed for web applications include HTML/CSS validation or cross-browser tests. Many of these tests can and should be automated whenever possible.