Bower: Your project can stop working at any moment because its dependencies can change.

Fabus Zamza

If you're working on legacy projects or just not an up-to-date one, you may be asking to install Bower. Bower is a package manager for managing front-end component such as Javascript or CSS files. For example, the Twitter Bootstrap framework version 3 is still using Bower for downloading JavaScript and CSS libraries.

One problem is that Bower is now considered a deprecated tool and Yarn is a new replacement. So if you've just installed Bower then it's very likely that you visit this page because you saw the following warning message pops up after install Bower:

npm WARN deprecated bower@1.8.2: ...psst! Your project can stop working at any moment because its dependencies can change. Prevent this by migrating to Yarn:

This is not an error, this is a warning message

The message above does NOT mean that the system has encountered an error during the installation process. Instead if there's no other error message and it means Bower has been installed successfully and you can use it right afterward. Check its version by running the following command on terminal:

$ bower -v

The reason why we see this warning message is because Bower is obsolete and should be used mainly for maintenance purpose. You can still use Bower for old projects but for new one you should consider using other tool. The author recommend us to use Yarn.

A package manager is just a software package but it is used to manage other software packages. Popular package managers such as Node Package Manager, Composer, RVM... are all de-factor tools for developers since using those software help use easily install/uninstall or update software packages used in our projects or even to be installed and used on system-wide basis (think like Rake gem in Ruby or Laravel package in PHP).