Bis-ortho-diynylarene (BODA) monomers, prepared from common bisphenols in three high yielding steps, undergo free-radical-mediated thermal polymerization via an initial Bergman cyclo-rearrangement. Polymerization is carried out at 210 degrees C in solution or neat with large pre-vitrification melt windows (4-5 h) to form branched oligomers containing reactive pendant and terminal aryldiynes. Melt- and solution-processable oligomers with weight-average molecular weight M-w = 3000-24 000 g mol(-1) can be coated as a thin film or molded using soft lithography techniques. Subsequent curing to 450 degrees C affords network polymers with no detectable glass transition temperatures below 400 degrees C and thermal stability ranging from 0.5-1.5 % h(-1) isothermal weight loss measured at 450 degrees C under nitrogen. Heating to 900-1000 degrees C gives semiconductive glassy carbon in high yield. BODA monomer synthesis, network characterization and kinetics, processability, thin-film photoluminescence, and thermal properties are described.