Welcome to the Cornell Theory Center's series of modules on programming using MPI, which stands for Message Passing Interface. Our first module is Basics of MPI Programming. We will give an overview of MPI, including a brief history of it's development and the importance of having a standard message passing library to do distributed parallel computing. We'll use a sample program to show what the contents of an MPI message actually look like and to illustrate the six basic MPI commands that you will need to start using MPI. Subsequent modules in this series will cover communication techniques, including point to point and collective communication in detail. Increasingly sophisticated sample programs will be introduced in these modules to illustrate when and why these different communication types should be used in your MPI programs.