Kodak Xtol Professional B&W Film Developer is one of the very best there is...you just know that whatever you put in it will come out lovely.
For that simple reason and the fact that it's know timing cover just about every black and whie film out there it is very useful, it's great also for films that are: normally exposed, or require push or pull processing for which it can provide more emulsion speed (shadow detail)
It offers full emulsion speed and easy mixing, in a variety of equipment, from small tanks (8 to 64 fluid ounces), trays, or rotary tubes to high-volume processors.
Featuring very high image quality at full emulsion speed, Fine grain and high sharpness, Convenient room-temperature mixing.
Note: If five litres is too much for you then go for the BelliniFoto Eco-Film, a liquid version that comes in more manageable volumes