It's a feature introduced in 5.3 and in the latest PHP 6 helping to resolve class and object run time association and hereby helping to resolve our needs.
The Web Notifications API is "an API for front-end user notifications". A notification allows the user to see alerts outside the context of a web page of an occurrence such as delivery of mail, user login, chat notification, process complete etc. The notifications will be in different style on different browser and based on the device we use. In mobile we usually see the notification in notification bar.
Composer is a tool for dependency management in PHP. It allows you to declare the dependent libraries for your project needs. It will install them in your project for you.
In the dynamic web we have to keep track of user information and we need to store some data in client machine either for browser session or persistent upto a period. There are many advantages on storing data like reducing server request, increase performance and totally working offline.
HHVM is the execution engine for PHP developed by facebook and opensourced in early 2010. It is termed as HipHop for PHP. It increases web page generation by factors of up to 9 over Zend PHP. This engine compile PHP source into a high level bytecode(intermediate language). Bytecode is then translated into x64 machine code dynamically at the run time using Just-in-time(JIT) compiler.
Twitter Bootstrap is a CSS framework that helps in designing web applications. It is one of the easiest CSS frameworks to use in the Industry today. It assumes you have no designing knowledge and all you want to do is write some HTML as per the Bootstrap specifications. In short, Twitter Bootstrap has already written a CSS style sheet for you, has inbuilt jQuery support and also has some popular JavaScript tools. Wooh! Isn’t that great? You get a bunch of popular tools ready to use. All you have to do is just place the right HTML mark-up at correct place.