diff --git a/MBS.Framework/Application.cs b/MBS.Framework/Application.cs
index a1b160e..1b6caca 100755
--- a/MBS.Framework/Application.cs
+++ b/MBS.Framework/Application.cs
@@ -364,12 +364,25 @@ namespace MBS.Framework
 			Initialized = true;
 		}
 
+		public event ApplicationActivatedEventHandler BeforeActivated;
+		protected virtual void OnBeforeActivated(ApplicationActivatedEventArgs e)
+		{
+			BeforeActivated?.Invoke(this, e);
+		}
+
 		public event ApplicationActivatedEventHandler Activated;
 		protected virtual void OnActivated(ApplicationActivatedEventArgs e)
 		{
 			Activated?.Invoke(this, e);
 		}
 
+
+		public event ApplicationActivatedEventHandler AfterActivated;
+		protected virtual void OnAfterActivated(ApplicationActivatedEventArgs e)
+		{
+			AfterActivated?.Invoke(this, e);
+		}
+
 		protected virtual int StartInternal()
 		{
 			CommandLine cline = new CommandLine();
@@ -413,14 +426,61 @@ namespace MBS.Framework
 			}
 
 			ApplicationActivatedEventArgs e = new ApplicationActivatedEventArgs(true, ApplicationActivationType.CommandLineLaunch, cline);
+
+			if (CommandLine.Options["help"]?.Value is bool && ((bool)CommandLine.Options["help"]?.Value) == true)
+			{
+				if (ShowCommandLineHelp(out int resultCode))
+				{
+					return resultCode;
+				}
+			}
+
 			if (cline.Command != null && cline.Command.ActivationDelegate != null)
 			{
+				OnBeforeActivated(e);
+				if (!e.Success)
+				{
+					Console.WriteLine(String.Format("Try '{0} --help' for more information.", ShortName));
+					return e.ExitCode;
+				}
+
 				// use the activation delegate instead of calling OnActivated
 				cline.Command.ActivationDelegate(e);
+				if (!e.Success)
+				{
+					Console.WriteLine(String.Format("Try '{0} --help' for more information.", ShortName));
+					return e.ExitCode;
+				}
+
+				OnAfterActivated(e);
+				if (!e.Success)
+				{
+					Console.WriteLine(String.Format("Try '{0} --help' for more information.", ShortName));
+					return e.ExitCode;
+				}
 			}
 			else
 			{
+				OnBeforeActivated(e);
+				if (!e.Success)
+				{
+					Console.WriteLine(String.Format("Try '{0} --help' for more information.", ShortName));
+					return e.ExitCode;
+				}
+
 				OnActivated(e);
+				if (!e.Success)
+				{
+					Console.WriteLine(String.Format("Try '{0} --help' for more information.", ShortName));
+					return e.ExitCode;
+				}
+
+				OnAfterActivated(e);
+				if (!e.Success)
+				{
+					Console.WriteLine(String.Format("Try '{0} --help' for more information.", ShortName));
+					return e.ExitCode;
+				}
 			}
 			return e.ExitCode;
 		}
@@ -428,12 +488,32 @@ namespace MBS.Framework
 
 		protected void PrintUsageStatement(CommandLineCommand command = null)
 		{
+			string shortOptionPrefix = CommandLine.ShortOptionPrefix ?? "-";
+			string longOptionPrefix = CommandLine.LongOptionPrefix ?? "--";
+
 			Console.Write("usage: {0} ", ShortName);
 			foreach (CommandLineOption option in CommandLine.Options)
 			{
 				PrintUsageStatementOption(option);
 			}
+
+			if (CommandLine.HelpTextPrefix != null)
+			{
+				Console.WriteLine();
+				Console.WriteLine();
+				Console.WriteLine(CommandLine.HelpTextPrefix);
+			}
+
 			Console.WriteLine();
+
+			bool printDescriptions = true;
+			if (printDescriptions)
+			{
+				foreach (CommandLineOption option in CommandLine.Options)
+				{
+					Console.WriteLine("  {0}{1}", option.Abbreviation != '\0' ? String.Format("{0}{1}, {2}{3}", shortOptionPrefix, option.Abbreviation, longOptionPrefix, option.Name) : String.Format("{0}{1}", longOptionPrefix, option.Name), option.Description == null ? null : String.Format(" - {0}", option.Description));
+				}
+			}
 			// Console.Write("[<global-options...>]");
 
 			if (command != null)
@@ -462,6 +542,12 @@ namespace MBS.Framework
 					}
 				}
 			}
+
+			if (CommandLine.HelpTextSuffix != null)
+			{
+				Console.WriteLine();
+				Console.WriteLine(CommandLine.HelpTextSuffix);
+			}
 		}
 
 		private void PrintUsageStatementOption(CommandLineOption option)
@@ -543,6 +629,10 @@ namespace MBS.Framework
 							index++;
 							option.Value = args[index];
 						}
+						else
+						{
+							option.Value = true;
+						}
 
 						if (list != null)
 							list.Add(option);
@@ -573,6 +663,10 @@ namespace MBS.Framework
 						// option.Value = args[index];
 						option.Value = value;
 					}
+					else
+					{
+						option.Value = true;
+					}
 					list.Add(option);
 				}
 				else
@@ -832,5 +926,13 @@ namespace MBS.Framework
 		{
 			_settings[id] = value;
 		}
+
+		protected virtual bool ShowCommandLineHelp(out int resultCode)
+		{
+			// bash: cd returns 2 if --help is specified OR invalid option selected, 1 if file not found
+			PrintUsageStatement();
+			resultCode = 2;
+			return true;
+		}
 	}
 }
diff --git a/MBS.Framework/ApplicationActivatedEvent.cs b/MBS.Framework/ApplicationActivatedEvent.cs
index 8dbfa1e..0a27f40 100755
--- a/MBS.Framework/ApplicationActivatedEvent.cs
+++ b/MBS.Framework/ApplicationActivatedEvent.cs
@@ -25,6 +25,8 @@ namespace MBS.Framework
 {
 	public class ApplicationActivatedEventArgs : EventArgs
 	{
+		public bool Success { get; set; } = true;
+
 		public bool FirstRun { get; } = true;
 		public CommandLine CommandLine { get; } = null;
 		public int ExitCode { get; set; } = 0;
diff --git a/MBS.Framework/ArrayExtensions.cs b/MBS.Framework/ArrayExtensions.cs
old mode 100755
new mode 100644
index 1ffcbfa..37775c4
--- a/MBS.Framework/ArrayExtensions.cs
+++ b/MBS.Framework/ArrayExtensions.cs
@@ -93,5 +93,13 @@ namespace MBS.Framework
 			}
 			return true;
 		}
+
+		public static T[] Concat<T>(T[] array1, T[] array2)
+		{
+			T[] array3 = new T[array1.Length + array2.Length];
+			Array.Copy(array1, 0, array3, 0, array1.Length);
+			Array.Copy(array2, 0, array3, array1.Length, array2.Length);
+			return array3;
+		}
 	}
 }
diff --git a/MBS.Framework/Collections/ExtensionMethods.cs b/MBS.Framework/Collections/ExtensionMethods.cs
index fb63319..48b6f33 100755
--- a/MBS.Framework/Collections/ExtensionMethods.cs
+++ b/MBS.Framework/Collections/ExtensionMethods.cs
@@ -26,6 +26,33 @@ namespace MBS.Framework.Collections
 {
 	public static class ExtensionMethods
 	{
+		public static bool ContainsAny<T>(this IEnumerable enumerable, T[] item)
+		{
+			foreach (object item1 in enumerable)
+			{
+				foreach (T item2 in item)
+				{
+					if (item1 is T)
+					{
+						if (item1.Equals(item2))
+							return true;
+					}
+				}
+			}
+			return false;
+		}
+		public static bool ContainsAny<T>(this System.Collections.Generic.IEnumerable<T> enumerable, T[] item)
+		{
+			foreach (T item1 in enumerable)
+			{
+				foreach (T item2 in item)
+				{
+					if (item1.Equals(item2))
+						return true;
+				}
+			}
+			return false;
+		}
 		public static T[] ToArray<T>(this IEnumerable enumerable) where T : class
 		{
 			System.Collections.Generic.List<T> list = new System.Collections.Generic.List<T>();
diff --git a/MBS.Framework/Collections/Generic/HandleDictionary.cs b/MBS.Framework/Collections/Generic/HandleDictionary.cs
index 25c8fa5..03489d6 100755
--- a/MBS.Framework/Collections/Generic/HandleDictionary.cs
+++ b/MBS.Framework/Collections/Generic/HandleDictionary.cs
@@ -43,6 +43,15 @@ namespace MBS.Framework.Collections.Generic
 			_dict.Add(handle, obj);
 		}
 
+		public bool ContainsObject(TObject obj)
+		{
+			return _dict.ContainsValue2(obj);
+		}
+		public bool ContainsHandle(THandle handle)
+		{
+			return _dict.ContainsValue1(handle);
+		}
+
 		public bool Contains(TObject obj)
 		{
 			return _dict.ContainsValue2(obj);
diff --git a/MBS.Framework/CommandLine.cs b/MBS.Framework/CommandLine.cs
index 1705c68..3df0825 100755
--- a/MBS.Framework/CommandLine.cs
+++ b/MBS.Framework/CommandLine.cs
@@ -39,6 +39,9 @@ namespace MBS.Framework
 
 		public CommandLineParser Parser { get; set; } = null;
 
+		public string HelpTextPrefix { get; set; } = null;
+		public string HelpTextSuffix { get; set; } = null;
+
 		public CommandLineOption.CommandLineOptionCollection Options { get; } = new CommandLineOption.CommandLineOptionCollection();
 		public CommandLineCommand.CommandLineCommandCollection Commands { get; } = new CommandLineCommand.CommandLineCommandCollection();
 		public CommandLineCommand Command { get; internal set; } = null;
diff --git a/MBS.Framework/CommandLineOptionValueType.cs b/MBS.Framework/CommandLineOptionValueType.cs
index ae6afc9..86f9936 100755
--- a/MBS.Framework/CommandLineOptionValueType.cs
+++ b/MBS.Framework/CommandLineOptionValueType.cs
@@ -23,8 +23,17 @@ namespace MBS.Framework
 {
 	public enum CommandLineOptionValueType
 	{
+		/// <summary>
+		/// The option accepts no values.
+		/// </summary>
 		None = 0,
+		/// <summary>
+		/// The option accepts a single value.
+		/// </summary>
 		Single = 1,
+		/// <summary>
+		/// The option accepts multiple values.
+		/// </summary>
 		Multiple = 2
 	}
 }
diff --git a/MBS.Framework/NanoId.cs b/MBS.Framework/NanoId.cs
index 4738a7c..d5c8d98 100755
--- a/MBS.Framework/NanoId.cs
+++ b/MBS.Framework/NanoId.cs
@@ -161,7 +161,9 @@ namespace MBS.Framework
 		}
 
 
-		private const string DefaultAlphabet = "_-0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+		public const string DefaultAlphabet = "_-0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+		public const string DefaultAlphabetNoSpecialChars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
 		private static readonly CryptoRandom Random = new CryptoRandom();
 		/// <summary>
 		///
diff --git a/MBS.Framework/Reflection.cs b/MBS.Framework/Reflection.cs
index d1df0bc..0e099a3 100755
--- a/MBS.Framework/Reflection.cs
+++ b/MBS.Framework/Reflection.cs
@@ -97,6 +97,7 @@ namespace MBS.Framework
 		}
 
 
+		private static object available_assemblies_lock = new object();
 		private static Assembly[] mvarAvailableAssemblies = null;
 		/// <summary>
 		/// Gets the available assemblies in the given search paths, or the current application directory if no search paths are specified.
@@ -105,7 +106,7 @@ namespace MBS.Framework
 		/// <param name="searchPaths">An array of <see cref="string" /> paths to search in.</param>
 		public static Assembly[] GetAvailableAssemblies(string[] searchPaths = null)
 		{
-			if (mvarAvailableAssemblies == null)
+			if (mvarAvailableAssemblies == null || searchPaths != null)
 			{
 				List<Assembly> list = new List<Assembly>();
 
@@ -139,27 +140,40 @@ namespace MBS.Framework
 							Assembly asm = Assembly.LoadFile(FileName);
 							list.Add(asm);
 						}
-						catch
+						catch (Exception ex)
 						{
 						}
 					}
 				}
 
-				mvarAvailableAssemblies = list.ToArray();
+				if (searchPaths == null)
+				{
+					mvarAvailableAssemblies = list.ToArray();
+				}
+				else
+				{
+					return list.ToArray();
+				}
 			}
 			return mvarAvailableAssemblies;
 		}
 
 		private static Type[] mvarAvailableTypes = null;
-		public static Type[] GetAvailableTypes(Type[] inheritsFrom = null)
+		public static Type[] GetAvailableTypes(Type[] inheritsFrom = null, Assembly[] additionalAssemblies = null)
 		{
 			if (mvarAvailableTypes == null)
 			{
 				List<Type> types = new List<Type>();
 				Assembly[] asms = GetAvailableAssemblies();
-				for (int iAsm = 0; iAsm < asms.Length; iAsm++)
+				List<Assembly> listAsms = new List<Assembly>(asms);
+				if (additionalAssemblies != null)
 				{
-					Assembly asm = asms[iAsm];
+					listAsms.AddRange(additionalAssemblies);
+				}
+
+				for (int iAsm = 0; iAsm < listAsms.Count; iAsm++)
+				{
+					Assembly asm = listAsms[iAsm];
 					Type[] types1 = null;
 					try
 					{