Code auto-completion is of great help in agile development environments, where you're pumping out a new version as soon as possible. In such environments you need your IDE to be "as fast as you code", hence Netbeans can be of great assistance in such situations. The IDE will auto-complete your code (variable names / function references / library functions / classes / ids) wherever possible, so you can code at speed.

NetBeans has out-of-the-box support for Maven (NetBeans 6.7 and newer), which includes a repository browser.

Creating services fixed in development version 201609120002 onwards.

Very easy to learn, unlike e.g. Eclipse (which is probably the most flexible).

Open source means that developers can contribute changes to the code to have the IDE better serve them.

If a computer has a Java virtual machine (JVM), Netbeans can run on it. Netbeans can therefore run on a variety of operating systems such as Windows, *nix, and Mac OS.

Being free means no monetary investment at all. If for whatever reason the developer doesn't like this IDE, all he has given up is his time.

Netbeans not only debugs your code, and points out errors but also gives you hints on which sections of your code could be further optimized.