1. A method of transferring blocked records of data between a first program executing in a first computer system and a second program executing in a second computer system coupled to the first computer system, wherein: the first computer system and the second computer system are heterogeneous computer systems; a plurality of computer systems comprise the first computer system and the second computer system; a set of programs executing on the second computer system comprises the second program; said method comprising: A) establishing a first session between a first interface in the first computer system to a second interface in the second computer system; B) establishing a first pipe connection between the second interface and a standard input file in a first program in the set of programs executing on the second computer; C) receiving a first plurality of data records in the first interface from the first program; D) blocking the first plurality of data records received in step (C) into a first block of data; E) transmitting the first block of data from the first interface across the first session to the second interface; F) unblocking the first block of data transmitted in step (E) into the first plurality of data records; and G) transmitting the first plurality of data records through the first pipe connection from the second interface to the first program in the set of programs executing on the second computer.