Can a c# app share memory (or variables/classes) with antoher c# app?

Question

for example program A is a c# pinball game. can program B read the current score of program A pinball while playing? i know this can be accomplished by program A saving its score to a file on the hd every 4 seconds or so and program B reading this file every 4 seconds and updating the user interface, but there just be a way program B can just read the variables in program A. cheers all!