NTest

NTest is a free Othello/Reversi program created by Chris Welty (not to be confused with the other computer scientist named Chris Welty who worked on the IBM Watson project). 
NTest is a strong Othello program, with a high quality evaluation function and fast search algorithms. It has many features with the most important one, the display of the search evaluation for all possible moves. NTest is among the strongest programs in the world. It is able to do bitboard-based move generation and parallel searches on multiple CPU cores.
Other programs' opening books such as Edax's book can be used in NBoard, the GUI created by Chris Welty for NTest.