Suggest adding an inner class to NbProcessDescriptor, something like:

public static class MapFormatDescriptor extends NbProcessDescriptor {
  private FeatureDescriptor[] keys; // java.beans pkg
  public MapFormatDescriptor (String pname, String args, FeatureDescriptor[] keys) {
    super (pname, args);

    this.keys = keys;
  }
  public MapFormatDescriptor (String pname, String args, String info, FeatureDescriptor[] keys) {
    super (pname, args, info);
    this.keys = keys;
  }
  public FeatureDescriptor[] getKeys () { return keys; }
}

No other API changes are required, except making NbProcessDescriptor un-final. Compatible change. At your leisure:

- Various compilers, executors, etc. which use NbProcessDescriptor in conjunction with a MapFormat should be modified to store an NbProcessDescriptor.MapFormatDescriptor as the declared type of proper
ties in their system options. The initial value provided by such modules should include a list of keys as recognized by their map format, where the feature descriptor`s name is the literal key, and di
splay name and short descriptor should also be set to useful values, e.g. "repository", "Class path for Repository", "This variable contains a list of directories and archive files present in the Repo
sitory to be used during compilation.". This is more informative & precise information than the info arg to NbProcessDescriptor.

- Make com.netbeans.developer.editors.NbProcessDescriptor dummy class with MapFormatDescriptorEditor inner class. Unlike NbProcessDescriptorEditor, which is restricted by semantics to editing text (si
nce it has no knowledge of what the contents of the descriptor are), this editor knows exactly what is contained in the arguments, and can provide a full dialog or whatever permitting the user to brow
se available tokens, insert or delete them, and get a meaningful description of what each does as they are using it. Proped would always copy the keys param from one value to the next, just