The Rubik's Professor's Cube is a 5x5x5 variation of the original Rubik's Cube. The first version of this puzzle was invented in 1981 by Udo Krell, who took a regular 3x3x3 Rubik's Cube and expanded its mechanism. Starting in 1983, Krell's design for this puzzle was manufactured and sold by Uwe Mèffert. The Rubik's Brand (currently owned by Spin Master) only added this puzzle to their lineup later, in 1986. It is interesting to note that even though this puzzle was not invented by the Rubik's Brand, the name by which it's known today, "Professor's Cube", was coined by Ideal Toys (former owner of the Rubik's Brand) when this puzzle was marketed in the 1980s.
As with all odd-order variations of the Rubik's Cube, the centermost piece on each face is fixed to the mechanism of the cube. Aside from these pieces, there are 48 additional center pieces that are free to move around the puzzle, 8 corner pieces, and 36 edge pieces. Similarly to the Rubik's Revenge Cube (4x4x4), the most common approach for solving this 5x5x5 cube is called the "reduction" method. Focusing on solving the 3x3 center pieces and 3x1 edge pieces first - thus "reducing" the problem to a 3x3x3 puzzle, which can be solved using a regular Rubik's cube solving algorithms. This puzzle has only one parity case.
This puzzle has many moving parts, thus allowing a huge number of possible permutations. The number of possible permutations of the 5x5x5 Professor's Cube is just under 2.83x1074. The 5x5x5 Cube is an official WCA puzzle, and the current world record for solving it is 32.88 seconds. It was set by Max Park from the USA at the CubingUSA Nationals 2023 competition.