Instructions on Using the jBasic Interpreter: Download all files into a diretory. Make sure that the "CLASSPATH" environment variable includes the appropriate directories (probably your home directory and the current directory). Assuming that JLex and Java_Cup have been properly installed, do the following: 0. Compile the interpreter's main classes: "javac jbclasses.java" 1. Create the parser source code with "java java_cup.Main < jbp.cup" 2. Create lexical scanner source code with "java JLex.Main jbl.lex" 3. Compile the lexer: "javac jbl.lex.java" 4. Compile the parser: "javac parser.java" 5. Compile the interpreter: "javac jbinterp.java" 6. Test if it works: "java jbinterp < factorial.jb" If all went well you'll see "The factorial of 5 is 120" printed on the screen. NOTE: you should be wondering why you would process the parser before the lexer. It's because by processing the .cup file Java_Cup will produce a file called "sym.java" that defines constants for each type of token. The "sym" class is then used by JLex so that the object returned with each token corresponds with what the parser expects to get.