Hello to everyone reading this: I'm here to announce that PocketMine-MP is now using Composer for dependency and autoloader management. Hold on. What is Composer? Composer is a dependency manager for PHP project. Using it means that PocketMine-MP can now use third-party libraries for implementing things instead of writing in-house implementations or copy-pasting code into the project. Read more about Composer here. How does this affect me? If you are using a source-code installation of PocketMine-MP (git clone for example) you will now need Composer to initialize the autoloader and install dependencies required by PocketMine-MP. This does not affect installations using prebuilt phars obtained from Jenkins, since Jenkins handles autoloader generation and dependency installation automatically. This means that Jenkins phars will automatically include all necessary autoloader files and dependency packages. Where can I get Composer for my system? If you have updated your PHP binary from official sources recently, you'll already have a composer.phar in your PHP binary's `bin` folder. If you want to install Composer manually, you can do so by following the instructions here. Help! It's telling me "Composer autoloader not found" when I try to start the server! This message means exactly what it says. Initializing the autoloader is easy: With the local composer.phar provided with our PHP packages Code: $ bin/php7/bin/php bin/composer.phar install With a global Composer installation: Code: $ composer install Updating dependencies when updating PocketMine-MP Also very simple. This is the same as the `install` process, just substitute `update` for `install`. It is crucial that you remember to update dependencies when you update a source-code installation.