The isCOBOL Compiler is a Java program. Every time you launch the Compiler, a JVM must be initialized. This operation may take a couple of seconds. If this couple of seconds is spent for each program, then the compilation of a series of programs may take several seconds. For this reason it’s good practice to compile multiple programs at once, using wildcard characters on the command line. For example a command like:

Takes less time than:

The display on console of the Compiler output has a little cost. If you wish to save more seconds in the compilation of multiple programs, you should consider to redirect the Compiler output to a file that you will review when the Compiler terminates, e.g.