The basic concept of PADE is to provide a development console for the virtual machine, so that all essential parallel development tasks can be carried out at a central location. This central location, the development host, is the computer where all source files for the parallel application are kept and is where PADE is executed. PADE provides a graphical interface to the operations of the virtual machine. PADE allows the following tasks to be performed on the development host, with transparent access to the other nodes of the virtual machine:
A graphical interface is an essential aid for keeping track of the application, as it enables one to visualize how the various parts of the application are distributed across the virtual machine. The current release of PADE offers a ``tree view'' representation of the virtual machine, which shows the nodes and their associated program files on a two-dimensional diagram. Many of the file and command management actions that are required during application development can be carried out by familiar ``click and drag'' operations on objects in this diagram, which simplifies much routine administrative work that would otherwise distract the programmer's attention.
Parallel application development is an evolving art, whose future needs are difficult to envisage. We have therefore designed PADE to be extensible and configurable by the user. This has been done by building PADE from standard software components. These components all have open definitions, are freely and widely available over the Internet, and have been relatively robust over time. Many of them will probably already have been installed on a workstation in a typical scientific or engineering environment. If any of the components are not installed, the user user can install them without having root privileges.