As part of the Message-Passing Programming (EPCC11002) course, I developed a parallel implementation of a 2D-decomposed cellular automaton with periodic boundary conditions on the \(i^{th} \) dimension. The boundary conditions for \( \frac{2}{3} \)​ of the \( j^{th} \) dimension are set to alive cells. A termination condition is imposed for the simulation in which the program terminates if the number of living cells is below 3/4 or greater than 4/3 of the initial living cells. The implementation uses MPI and a cartesian virtual topology to decompose the grid into two dimensions where each process receives a subsection of the grid. Communication between processes is performed using halo-swapping via non-blocking point-to-point communication (MPI_Isend and MPI_Irecv).