Virtual screening enables searching and ranking millions of virtual molecules at a low cost. A key aspect for success is to search synthesizable virtual molecules and to provide a representative search space covering interesting chemical space. The exploration of explicitly enumerated molecules is limited due to computational resources and search times. Therefore, AZ investigated the exploration of the AZ-virtual chemistry space using FTrees-FS, which does not require any enumeration of molecules, and compared results to explicitly enumerated libraries. The definition of the AZ-virtual chemistry space provides access to a large and diverse chemical space ready for synthesis allowing for quick turn-around times and syntheses.