Although the idea of dependency management is not new and considered to be a fundamental development practice, it is not widely adopted by the PHP community. Composer is a tool for dependency management in PHP. It is strongly influenced by tools from other technology stacks like Node's npm and Ruby's Bundler. We are now seeing wide adoption across PHP projects and it is fairly mature. You can still have to do some shims for internal libraries, you can use it for most external libraries.
Although the idea of dependency management is not new and considered to be a fundamental development practice, it is not widely adopted by the PHP community. Composer is a tool for dependency management in PHP. It is strongly influenced by tools from other technology stacks like Node's npm and Ruby's Bundler.