There are several developers which have been formulated to lower the contrast of high contrast films to allow their use for pictorial photography.
o Burton Developer
o Collins Extended Range Developer
o Delagi #8 Developer
o HFD-301 Developer
o Hode Low Gamma Developer, US Pat 4205124
o H & W Control Developer
o Kodak SD-2415
o Perfection XR-1 Developer, US Pat 4083722
o Photo Optics Technical Area US Army (POTA Developer)
o TDLC-103 Developer
o XDR-4 Developer
The formulas can be found either on APUG or on the web. I have tried many of them but have never found one that gave more than just acceptable results. So good luck and be prepared to do some experimenting. To a large extent the contrast of these high contrast films is built in.