Wann develop some photographic paper? Here's 1L of concentrate this will make 5L working solution. 

Here is what Ilford say:

ILFORD MULTIGRADE is a liquid concentrate developer, suitable for the dish/tray developing of all black & white photographic paper, but especially designed to obtain the best possible results from the ILFORD MULTIGRADE range of papers.

MULTIGRADE developer has excellent keeping properties and gives a neutral image tone with most darkroom papers. Supplied as a concentrate, this developer is typically used at a dilution of 1+9, but can also be used at 1+14 for greater development control and economy.