With this collection of short review papers we would like to present a broad overview of research on poly?uorenes and related heteroanalogues over the last two decades. The collection begins with papers on the synthesis of po- ?uorenesandrelatedpolyheteroarenes, thenreportsphotophysicalproperties of this class of conjugated polymers both at the ensemble and the single chain level, continues with a discussion of the rich solid state structures of poly?uorenes, and ?nally switches to device applications (e.g. in OLEDs). In addition, two chapters are devoted to de?ned oligo?uorenesas...