The Emergency Medical Hologram Replacement Program was a holographic replacement for The Doctor created by Harry Kim at the request of Tom Paris.
When The Doctor was transferred to the USS Prometheus in the Alpha Quadrant, Paris was left in charge of sickbay. Unsatisfied with his possible permanent job (with thoughts of The Doctor not returning) and wanting to remain as the pilot of the USS Voyager, he called upon Harry Kim to create a replacement.
The replacement looked exactly like the EMH Mark I, though Paris wanted to include more hair and give it a different personality.
Kim downloaded the ship's entire medical library and compressed it into a single data file. It contained all the "classics", from Gray's Anatomy to Leonard McCoy's Comparative Alien Physiology. When the file was entered into the replacement program, the EMHRP started to recite the documentation it had received, starting with Gray's Anatomy Chapter 1.
With no speech recognition protocols yet, because Harry had not installed them, the EMHRP would not stop talking, despite Paris yelling at it to "be quiet for a minute". The program eventually overloaded and went offline. The project was considered a failure. (VOY: "Message in a Bottle")