Recent representative molecular diversity studies include the analysis of novel libraries, such as compounds applied in the food industry , peptides , focused libraries , de novo virtual libraries , and commercially available fragments libraries for medicinal chemistry . The results are summarized in Table . For these analyses, new molecular representations and visualization techniques were implemented. For instance, the chemical space of food compounds stored in FooDB was analyzed using ChemMaps, an approach based on reference or "satellite" compounds, that is, molecules whose distance (or similarity) to all other molecules in the chemical space yield sufficient information to produce a visual representation of the space . In principle, it is possible to generate a 3D visual representation of chemical space using satellite structures. TMAP was used in the global analysis of the peptide chemical space, whereas MAP4 was employed as the molecular representation of peptides . A similar approach was used to visualize the chemical space of NPs in the public domain . To assist the processes of decision-making and selecting compound libraries for further virtual screening or compound acquisition for high-or medium-throughput screening for epigenetic drug discovery, Flores-Padilla et al. reported a comprehensive analysis of 11 commercial libraries of varying sizes focused on epigenetic targets (with 53,443 compounds in total) . Analysis of the chemical diversity and coverage of chemical space was conducted with Constellation plots based on the chemical core scaffolds and CLNs . The latter is based on structural fingerprints and facilitates the visual representation of the chemical space of compound datasets with a significant number (millions) of compounds in an efficient manner. The analysis highlighted a commercial library with an extensive coverage of chemical space (despite low intra-molecular diversity) and identified compound collections that cover unique regions of the chemical space not populated by other epigenetic-focused libraries.