With a Stack we provide an other level of simplicity used by the feature Project.
A Stack is a
pile who can only contain links to public packages (hosted on Packagist.org) and private packages (hosted on harmony Marketplace).
By example, if you choose the database MongoDB for your project, we will link the stack named MongoDB. This stack will tell to HarmonyFlex to execute the command
composer config "platform.ext-mongo" "1.6.16" and install the next packages: