Pimcore 5.4 makes Pimcore a Composer Library
Pimcore is now a Composer Library
Composer is an application-level package manager for the PHP programming language that provides a standard format for managing dependencies of PHP software and required libraries. Composer runs through the command line and installs dependencies (e.g. libraries) for an application. It allows users to install PHP applications that are available on Packagist which is its main repository containing available packages. It provides autoload capabilities for libraries that specify autoload information to ease usage of third-party code.
Pimcore is now located in /vendor/pimcore/pimcore and no longer in the /pimcore folder. Because of that, Pimcore will no longer be part of the Git Repo, but will be treated like any other dependency. In addition, the project-specific composer.json will be much clearer, an example can be found here. In the course of this, the folder structure of the main repository of Pimcore has also changed a bit. Short version: everything that used to be in /pimcore is now one level higher, the project-specific files & folders are now in their own repositories, eg:
Pimcore is updated via Composer
The old, GUI-based updater has served its purpose. In the future, Pimcore will be updated by Composer, like all other dependencies. So of course it is important to always have the correct version constraint in composer.json for pimcore/pimcore. Example: If you have Constraint 5.4.* and you are currently on 5.4.0 - but the most current version is 5.4.3 - then a composer update automatically updates to 5.4.3. We expect much more stable, massively faster and less problematic updates. Additional sweet stuff you might like:
Core Migrations (update scripts from Pimcore) can now be executed manually:
./bin/console pimcore: migrations: migrate -s pimcore_core
Rollbacks will almost always be possible
Visit the Pimcore developer community forums.