      behavior of <b>XERROR</b> in software they are using.  The package
      includes many routines to customize its behavior, to reduce
      the level of output, to make multiple copies of the error output,
      to control the number of times a particular error message is printed,
      or to halt execution of the program if certain kinds of error occur.
    </p>

    <h3 align = "center">
      Languages:
    </h3>

    <p>
      <b>XERROR</b> is available in
      <a href = "../../f77_src/xerror/xerr