Cucumber - Cucumber is a BDD tool for specification of application features and user scenarios in plain text.
WritePHPOnline.Com - WritePHPOnline.Com is an online site that enables you to write code in PHP and view its output.
Capybara - Capybara helps you test web applications by simulating how a real user would interact with your app.
PHPTester.net - PHPTester.net gives developers and learners the ability to write their PHP code and get the output online.
RSpec - RSpec is a testing tool for the Ruby programming language born under the banner of Behavior-Driven Development featuring a rich command line program, textual descriptions of examples, and more.
Rapid PHP - Rapid PHP editor is the world's fastest and lightest PHP IDE for Windows with code intelligence and tools for PHP, HTML, CSS, and JavaScript, including PHP debugger, FTP/SFTP client, UTF-8 support and more.