For those who are not familiar with it, PHAR (Php Archive) is analogous to the JAR file concept but for PHP. It allows you to package an application into a single file making it convenient to deploy or distribute.
[...] So what are PHARs useful for then? Well still the same thing: packaging applications. Although not many people may want to use this technique for web applications, it is still extremely useful for console applications.
The tutorial starts off by showing a few different methods for installing Phars and how to build them from your code. While they can be built manually, he suggests using the box project to help make it simpler. It also covers self-updating phars and shows how to update the
box.json configuration to use a generated key to sign the release. Finally it covers a method for using Travis-CI to auto-build the phar and how to keep the OpenSSL key safe and out of the checked in code.