Fragment-based drug discovery (FBDD) has become a staple and invaluable tool for probing targets and generating hits. The foundation of all fragment-to-lead projects rests on the underlying libraries. While many efforts have been made to optimise these libraries for diversity, chemical space coverage, and their properties, their developability has often been overlooked. The progression of a fragment, which is often merely a weak binder, is frequently hindered by synthetic challenges but should ideally not require excessive time and resources. Instead, one desires a “sociable” fragment with numerous commercial analogues available, allowing all growth vectors to be accessed with different substituents....