At least some of the interconnection signaling on a programmable logic device (“PLD”) is by differential signaling using differential driver circuitry to apply differential signals to a pair of conductors that extend to differential receiver circuitry. Such differential interconnection signaling helps the PLD operate satisfactorily with lower power supply voltages. The conductors in each differential signaling pair may cross over one another at various intervals in order to help reduce the adverse effects of capacitive coupling between adjacent and parallel signaling paths.