You can either load an executable program into Prism, or start from the beginning by calling up an editor and a UNIX shell within Prism and using them to write and compile the program.
Once an executable program is loaded into Prism, you can (among other things):
Execute the program
Debug the program
Visualize data from the program
Analyze the performance of message-passing programs
Prism supports two modes of operation, depending upon whether you are developing message-passing programs (MP Prism) or serial programs (scalar Prism). When running serial programs under Prism, the view presented to the user is usually that of a single serial program. When running message-passing programs under Prism, additional features (such as pset support) become available.