Thinking more...

//Simple usage, it will display in help
[assembly: Mono.UsageComplement("[-t:param] [-o] [-h] [-v] [-u]")]
//Description about this program
[assembly: Mono.About("A sample about how to use Mono.GetOptions")]
//Author
[assembly: Mono.Author("your_name")]
//If this program has bugs, user can report bugs to whom.  This is optional.
[assembly: Mono.ReportBugsTo("your_name@your_domain.com")]
//More detail description.  This is optional.
[assembly: Mono.AdditionalInfo("This is a sample about how to use Mono.GetOptions.  It's only a small program.  If you want to know more about Mono.GetOptions, you can hack Mono.GetOptions source code.")]
//Belong to which package.  This is optional.
[assembly: Mono.IsPartOfPackage("Samples")]

[assembly: AssemblyTitle("Mono.GetOptions Sample")]
[assembly: AssemblyProduct("getoptions_sample")]
[assembly: AssemblyCopyright("your_name or your_organization")]
[assembly: AssemblyVersion("1.0.*")]

using Mono.GetOptions;

using System.Collections.Generic;
class ProgramOptions : Options
{
 private string _outputFolder = "output";

 public string OutputFolder
 {
  get { return _outputFolder; }
  set { _outputFolder = value; }
 }

 private List _templateFolders;

 // Max occurance are 2, you can use -t or --template
 // Usage: -t:test or --template:test
 [Option(2, "Template folder, default is 'default'", 't', "template")]
 public WhatToDoNext DoTemplate( string s )
 {
  //Console.WriteLine( "template={0}", s );
  _templateFolders.Add( s );
  return WhatToDoNext.GoAhead;
 }

 // Default allow occurs once, option is -o or --output
 [Option("Output folder, default is 'output'", 'o', "output")]
 public WhatToDoNext DoOutput( string s )
 {
  //Console.WriteLine( "output={0}", s );
  _outputFolder = s;
  return WhatToDoNext.GoAhead;
 }

 public ProgramOptions()
 {
  // Accept Linux / Windows
  this.ParsingMode = OptionsParsingMode.Both;

  _templateFolders = new List();
 }
}

ProgramOptions options = new ProgramOptions(); 
options.ProcessArgs(args);
foreach( string s in options.TemplateFolders )
 Console.WriteLine( "Template folder = {0}", s );
Console.WriteLine( "Output folder = {0}", options.OutputFolder );

#your_program -h
#your_program --help
#your_program --template:t1 --template:t2 --output:o1
#your_program -t:t1 -t:t2 -o:o1
#your_program -u
#your_program -V
#your_program --version