• Break: The install command now has --dev enabled by default. --no-dev can be used to install without dev requirements
• Added composer-plugin package type to allow extensibility, and deprecated composer-installer
• Added psr-4 autoloading support and deprecated target-dir since it is a better alternative
• Added --no-plugins flag to replace --no-custom-installers where available
• Added global command to operate Composer in a user-global directory
• Added licenses command to list the license of all your dependencies
• Added pre-status-cmd and post-status-cmd script events to the status command
• Added post-root-package-install and post-create-project-cmd script events to the create-project command
• Added pre-autoload-dump script event
• Added --rollback flag to self-update
• Added --no-install flag to create-project to skip installing the dependencies
• Added a hhvm platform package to require Facebook's HHVM implementation of PHP
• Added github-domains config option to allow using GitHub Enterprise with Composer's GitHub support
• Added prepend-autoloader config option to allow appending Composer's autoloader instead of the default prepend behavior
• Added Perforce support to the VCS repository
• Added a vendor/composer/autoload_files.php file that lists all files being included by the files autoloader
• Added support for the no_proxy env var and other proxy support improvements
• Added many robustness tweaks to make sure zip downloads work more consistently and corrupted caches are invalidated
• Added the release date to composer -V output
• Added autoloader-suffix config option to allow overriding the randomly generated autoloader class suffix
• Fixed BitBucket API usage
• Fixed parsing of inferred stability flags that are more stable than the minimum stability
• Fixed installation order of plugins/custom installers
• Fixed tilde and wildcard version constraints to be more intuitive regarding stabilities
• Fixed handling of target-dir changes when updating packages
• Improved performance of the class loader
• Improved memory usage and performance of solving dependencies
• Tons of minor bug fixes and improvements