Scripts for the ESX framework, covering jobs, housing, interfaces, economy and utilities. ESX resources depend on es_extended and its shared object, so they expect an ESX server rather than QBCore or a standalone setup.
ESX has several generations in active use, and that is where most installation trouble starts. Older resources written for ESX 1.1 call functions that later releases moved or renamed, while ESX Legacy resources assume the newer structure. Check which generation a listing targets against what your server runs. Check the database layer too: a script expecting oxmysql will not run on mysql-async without changes. If a listing does not state its ESX generation, treat that as a question to ask before buying, not a detail to discover after.