Program Design Language

Program Design Language (or PDL, for short) is a method for designing and documenting methods and procedures in software. It is related to pseudocode, but unlike pseudocode, it is written in plain language without any terms that could suggest the use of any programming language or library.

PDL was originally developed by the company Caine, Farber & Gordon and has been modified substantially since they published their initial paper on it in 1975. It has been described in some detail by Steve McConnell in his book Code Complete.

PSEUDOCODE

Pseudocode is an informal high-level description of the operating principle of a computer program or other algorithm.

It uses the structural conventions of a programming language, but is intended for human reading rather than machine reading. Pseudocode typically omits details that are not essential for human understanding of the algorithm, such as variable declarations, system-specific code and some subroutines. The programming language is augmented withnatural language description details, where convenient, or with compact mathematical notation. The purpose of using pseudocode is that it is easier for people to understand than conventional programming language code, and that it is an efficient and environment-independent description of the key principles of an algorithm. It is commonly used in textbooks and scientific publications that are documenting various algorithms, and also in planning of computer program development, for sketching out the structure of the program before the actual coding takes place.

No standard for pseudocode syntax exists, as a program in pseudocode is not an executable program. Pseudocode resembles, but should not be confused with skeleton programs, including dummy code, which can be compiled without errors. Flowcharts, drakon-charts and Unified Modeling Language (UML) charts can be thought of as a graphical alternative to pseudocode, but are more spacious on paper.
source:http://en.wikipedia.org/wiki/Pseudocode http://en.wikipedia.org/wiki/Program_Design_Language