Place a number of different pentominos in the grid. Rotations and reflections are considered the same pentomino. The pentominos aren't allowed to touch each other, not even diagonally. The numbers in the grid indicate how many white cells can be seen from that cell in all horizontal and vertical directions, including the cell itself. Pentomino pieces block their sight.
History of the puzzle
First appeared on the blog of Bram de Laat (Netherlands) in 2012.