What is “nailgun” Package?

Command-line client, protocol and server for Java programs
For more details: http://www.martiansoftware.com/nailgun/

Installation

• Open Terminal by pressing command+space then type terminal and hit Enter key.
• Install homebrew first.

  ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" < /dev/null 2> /dev/null

• Install nailgun.

  brew install nailgun

Now, use nailgun!