In computer programming, a p-code machine (portable code machine) is a virtual machine designed to execute "p-code" (the assembly language or machine code of a hypothetical central processing unit (CPU)). This term is applied both generically to all such machines (such as the Java virtual machine (JVM) and MATLAB precompiled code), and to specific implementations, the most famous being the p-Machine of the Pascal-P system, particularly the UCSD Pascal implementation, among whose developers, the "p" in "p-code" was construed to mean "pseudo" more often than "portable", thus "pseudo-code" meaning instructions for a pseudo-machine.