Anyway, it's pretty interesting, there are arguably three arms to this...
- Top left - screening compound databases (zinc, euos and emolecules)
- Bottom centre - patent databases (patents, ibm and surechem)
- Centre right - drug databases (drugbank, et al)
In the middle is Chembl itself, which sort of makes sense, as there will be fractionally more overlap with patent db's, available compounds, and drugs.