IDE stands for Integrated Development Environment. An IDE is a software application used by programmers for code development and debugging. It increases programmer productivity. The best IDE comes with a number of features and services to develop a custom application.

The Three Best IDEs:

1. Sublime Text 3

The good thing about sublime is it's lightweight, open source and is Cross Platform means it is supported on OS X, Windows and Linux.
Benefits of Sublime text editor is it provides lot of packages for code formatting, debugging etc . User has to find the packages using Ctrl+shift+P and then install. List of few packages are :

•   HTML/CSS/JS Prettify
•   Php code beautifier

Some of the core features of sublime text editor are highly beneficial for developers and this is the main reason why developers choose this IDE for development. Below are some of the core features listed:

•   Multiple selection functionality
•   Distraction Free Mode
•   Editing option in split screen
•   Cross Platform compatibility

For more detail on features and Installation process on different platforms visit below link:

https://www.sublimetext.com/

2) Eclipse  

Eclipse is popularly known for Java Development Environment of IBM and it's is also available for PHP too.

It is open-source and supported on Windows, Mac, Linux, Solaris and any other platform . Many libraries are already installed on it to provide following features.

• Intellisense
• Code organistaion
• syntax highlighting
• code formatter
• Good debugging tool with step by step breakpoints.
• All files can be viewed and managed at same screen.
• Git version control
• Since Eclipse tools are open source, they are quickly updated with the latest technology that can be integrated into existing code.

To install a new library :

Open Eclipse -> Right Click on project folder -> Properties -> "Java Build Path" -> click  "Add External JARS" button -> find and select the downloaded  .jar file -> Click ok -> library is added

For More Detail:
https://eclipse.org/ide/

3) Net Beans

Netbeans is a free and open source IDE of Oracle environment, written in java and was firstly developed for development based on Java language but it is a cross platform IDE which supports other languages like, PHP, HTMl5, C/C++ etc.

NetBeans PHP IDE is a complete package for all the php developers. It is supported on Windows, OSX and Linux.

• The IDE supports HTML5 , CSS3 and JavaScript.
• Few fetaures of NetBeans:
• Support major Php framework such as Zend, Symfony etc.
• Support version control system, GIT.
• Supports debugger.

To install a new library:

Open net beans -> Click on the project it will show libraries option -> Right click on the libraries -> Select the Jar that you want to install  -> Click ok -> library is added

For more:

https://netbeans.org/

I like Eclipse over NetBeans because Eclipse takes less time in initialization compare to Net Beans. Also the intelligence feature on Eclipse is better than that of NetBeans.

Or if user want to keep things simple and do not need extra features then user can go for sublime.

At last its users choice they should compare all the 3 IDEs features and should use according to their need.