They published Van Perlo. Their proprietary app allows you to tap the notation to move pieces on a digital board—vastly superior to a static PDF.
4. For the "Practical" Player: Practical Chess Endgames (Bernd Rosen)
While Van Perlo's Endgame Tactics is widely considered a masterpiece of chess literature, the quest for a "better" PDF or alternative often stems from a player's specific learning style. Whether you are looking for a more modern interface, more rigorous engine-checking, or a different pedagogical approach, there are several contenders that might actually serve your game better than a standard digital copy of Van Perlo.