diff --git a/Compile System Package.run.xml b/Compile System Package.run.xml
index 54ad48d..e7f56b5 100644
--- a/Compile System Package.run.xml	
+++ b/Compile System Package.run.xml	
@@ -1,7 +1,7 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Compile System Package" type="DotNetProject" factoryName=".NET Project">
     <option name="EXE_PATH" value="$PROJECT_DIR$/kscr-runtime/bin/Debug/net5.0/kscr.exe" />
-    <option name="PROGRAM_PARAMETERS" value="compile --system true --sources kscr-system/ --output kscr-runtime/bin/Debug/net5.0/std/" />
+    <option name="PROGRAM_PARAMETERS" value="compile --system --sources kscr-system/core/Throwable.kscr kscr-system/core/Iterator.kscr kscr-system/core/Iterable.kscr --output kscr-runtime/bin/Debug/net5.0/std/" />
     <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/" />
     <option name="PASS_PARENT_ENVS" value="1" />
     <option name="USE_EXTERNAL_CONSOLE" value="0" />
diff --git a/Test Execute.run.xml b/Test Execute.run.xml
index d566354..6165709 100644
--- a/Test Execute.run.xml	
+++ b/Test Execute.run.xml	
@@ -1,7 +1,7 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Test Execute" type="DotNetProject" factoryName=".NET Project">
     <option name="EXE_PATH" value="$PROJECT_DIR$/kscr-runtime/bin/Debug/net5.0/kscr.exe" />
-    <option name="PROGRAM_PARAMETERS" value="execute --debug --sources kscr-system/core/Throwable.kscr examples/PrintNumbers.kscr --output examples/build/compile/" />
+    <option name="PROGRAM_PARAMETERS" value="execute --debug --sources examples/PrintNumbers.kscr --output examples/build/compile/" />
     <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/" />
     <option name="PASS_PARENT_ENVS" value="1" />
     <option name="USE_EXTERNAL_CONSOLE" value="0" />
diff --git a/examples/PrintNumbers.kscr b/examples/PrintNumbers.kscr
index bb6922c..63e277d 100644
--- a/examples/PrintNumbers.kscr
+++ b/examples/PrintNumbers.kscr
@@ -1,6 +1,7 @@
 package org.comroid.kscr.test;
 
 import org.comroid.kscr.core.Throwable;
+import org.comroid.kscr.core.Iterable;
 
 public class PrintNumbers implements Throwable {
     public static int StackSize -> 64;
@@ -12,10 +13,10 @@ public class PrintNumbers implements Throwable {
     
     // prints numbers 0 to 11
     public static void main() {
-        void range = 0~12; // todo: range as non-compile-time constant 
+        Iterable range = 0~12; // todo: range as non-compile-time constant 
         
         stdio << "print numbers " + range.start() + " to (exclusive) " + (range.end() - 1 + 1) + ":";
-        forn (i : range)
+        foreach (i : range)
             stdio << i;
         
         stdio << "and now backwards bcs we're cool:";
diff --git a/kscr-compiler/Class/ClassCompiler.cs b/kscr-compiler/Class/ClassCompiler.cs
index e1992ed..3811c3d 100644
--- a/kscr-compiler/Class/ClassCompiler.cs
+++ b/kscr-compiler/Class/ClassCompiler.cs
@@ -101,7 +101,7 @@ private void ResetData()
                     while (ctx.NextToken?.Type == TokenType.Word)
                     {
                         ctx.TokenIndex += 1;
-                        var cls = ctx.FindFullTypeInfo(vm) as IClassInstance;
+                        var cls = ctx.FindTypeInfo(vm) as IClassInstance;
                         if (cls == null)
                             throw new CompilerException(ctx.Token.SourcefilePosition,
                                 "Invalid extends-Token; Type not found");
@@ -120,7 +120,7 @@ private void ResetData()
                     while (ctx.NextToken?.Type == TokenType.Word)
                     {
                         ctx.TokenIndex += 1;
-                        var cls = ctx.FindFullTypeInfo(vm) as IClassInstance;
+                        var cls = ctx.FindTypeInfo(vm) as IClassInstance;
                         if (cls == null)
                             throw new CompilerException(ctx.Token.SourcefilePosition,
                                 "Invalid implements-Token; Type not found: " + ctx.NextToken?.Arg!);
@@ -138,7 +138,7 @@ private void ResetData()
                     if (targetType == null)
                     {
                         // is return type
-                        targetType = ctx.FindFullTypeInfo(vm);
+                        targetType = ctx.FindTypeInfo(vm);
                     }
                     else if (memberName == null)
                         // is name
diff --git a/kscr-compiler/Class/TypeParameterDefinitionCompiler.cs b/kscr-compiler/Class/TypeParameterDefinitionCompiler.cs
index 7bd0ce6..b96c6a2 100644
--- a/kscr-compiler/Class/TypeParameterDefinitionCompiler.cs
+++ b/kscr-compiler/Class/TypeParameterDefinitionCompiler.cs
@@ -1,4 +1,5 @@
-using KScr.Lib;
+using System.Linq;
+using KScr.Lib;
 using KScr.Lib.Bytecode;
 using KScr.Lib.Exception;
 using KScr.Lib.Model;
@@ -29,6 +30,9 @@ public TypeParameterDefinitionCompiler(ClassCompiler parent, IClass @class) : ba
                         if (pIndex >= _class.BaseClass.TypeParameters.Count)
                             throw new CompilerException(ctx.Token.SourcefilePosition, "Invalid TypeParameter index during compilation");
 
+                        var context = ctx;
+                        if (_class.TypeParameters.Any(x => x.Name == context.Token.Arg!))
+                            break;
                         _class.TypeParameters.Add(new TypeParameter(ctx.Token.Arg!));
                         pIndex += 1;
                         pState += 1;
diff --git a/kscr-compiler/Code/CodeCompiler.cs b/kscr-compiler/Code/CodeCompiler.cs
index cdbe7a3..e76cf90 100644
--- a/kscr-compiler/Code/CodeCompiler.cs
+++ b/kscr-compiler/Code/CodeCompiler.cs
@@ -99,7 +99,7 @@ protected AbstractCodeCompiler(ICompiler parent) : base(parent)
                     {
                         if (ctx.NextToken?.Type == TokenType.Word)
                         { // declaration
-                            CompileDeclaration(ctx,type);
+                            CompileDeclaration(ctx, type);
                         }
                         else
                         { // type expression
diff --git a/kscr-compiler/Code/StatementCompiler.cs b/kscr-compiler/Code/StatementCompiler.cs
index a8c7adc..9086e89 100644
--- a/kscr-compiler/Code/StatementCompiler.cs
+++ b/kscr-compiler/Code/StatementCompiler.cs
@@ -186,18 +186,18 @@ public StatementCompiler(ICompiler parent, bool endBeforeTerminator = false, par
                     ctx.LastComponent!.InnerCode = subctx.ExecutableCode;
                     ctx.TokenIndex = subctx.TokenIndex;
                     return this;
-                case TokenType.ForN:
+                case TokenType.ForEach:
                     if (ctx.NextToken?.Type != TokenType.ParRoundOpen)
                         throw new CompilerException(ctx.Token.SourcefilePosition, "Invalid forn-Statement; missing specification");
                     ctx.Statement = new Statement
                     {
                         Type = StatementComponentType.Code,
-                        CodeType = BytecodeType.StmtForN 
+                        CodeType = BytecodeType.StmtForEach
                     };
                     ctx.Component = new StatementComponent
                     {
                         Type = StatementComponentType.Code,
-                        CodeType = BytecodeType.StmtForN,
+                        CodeType = BytecodeType.StmtForEach,
                         SourcefilePosition = ctx.Token.SourcefilePosition
                     };
                     
@@ -216,7 +216,7 @@ public StatementCompiler(ICompiler parent, bool endBeforeTerminator = false, par
                     {
                         Type = StatementComponentType.Code,
                         CodeType = BytecodeType.Expression,
-                        TargetType = Lib.Bytecode.Class.RangeType.DefaultInstance
+                        TargetType = Lib.Bytecode.Class.IterableType.DefaultInstance
                     };
                     CompilerLoop(vm, new ExpressionCompiler(this, false, TokenType.ParRoundClose), ref subctx);
                     ctx.LastComponent!.SubStatement = subctx.Statement;
@@ -230,8 +230,6 @@ public StatementCompiler(ICompiler parent, bool endBeforeTerminator = false, par
                     ctx.LastComponent!.InnerCode = subctx.ExecutableCode;
                     ctx.TokenIndex = subctx.TokenIndex;
                     return this;
-                case TokenType.ForEach:
-                    throw new NotImplementedException("ForEach");
                 case TokenType.ParAccClose:
                     _active = false;
                     return this;
diff --git a/kscr-compiler/Tokenizer.cs b/kscr-compiler/Tokenizer.cs
index 0a53d73..ed6db1a 100644
--- a/kscr-compiler/Tokenizer.cs
+++ b/kscr-compiler/Tokenizer.cs
@@ -257,13 +257,10 @@ private void LexicalToken(bool isWhitespace, ref string str, char c,
                     token = new Token(srcPos, TokenType.While);
                     return;
                 case "for":
-                    if (n is 'n' or 'e')
+                    if (n is 'e')
                         break;
                     token = new Token(srcPos, TokenType.For);
                     return;
-                case "forn":
-                    token = new Token(srcPos, TokenType.ForN);
-                    return;
                 case "foreach":
                     token = new Token(srcPos, TokenType.ForEach);
                     return;
diff --git a/kscr-lib/Bytecode/Class.cs b/kscr-lib/Bytecode/Class.cs
index f75760b..657d189 100644
--- a/kscr-lib/Bytecode/Class.cs
+++ b/kscr-lib/Bytecode/Class.cs
@@ -23,6 +23,8 @@ public sealed class Class : AbstractPackageMember, IClass, IRuntimeSite
         public static readonly Class StringType = new(LibClassPackage, "str", true, MemberModifier.Public | MemberModifier.Final);
         public static readonly Class RangeType = new(LibClassPackage, "range", true, MemberModifier.Public | MemberModifier.Final);
         public static readonly Class NumericType = new(LibClassPackage, "num", true, MemberModifier.Public | MemberModifier.Final) { TypeParameters = { new TypeParameter("T") } };
+        public static readonly Class IteratorType = new(LibClassPackage, "Iterator", true, MemberModifier.Public, ClassType.Interface) { TypeParameters = { new TypeParameter("T") } };
+        public static readonly Class IterableType = new(LibClassPackage, "Iterable", true, MemberModifier.Public, ClassType.Interface) { TypeParameters = { new TypeParameter("T") } };
         public static readonly Class ThrowableType = new(LibClassPackage, "Throwable", true, MemberModifier.Public, ClassType.Interface);
         public static readonly Instance NumericByteType = new(NumericType, (ITypeInfo) 
             new Class(LibClassPackage, "byte", true, MemberModifier.Public | MemberModifier.Final));
@@ -93,7 +95,7 @@ public Instance CreateInstance(RuntimeBase vm, Class? owner = null, params IType
 
         public Class BaseClass => this;
         public List<ITypeInfo> TypeParameters { get; } = new();
-        public TypeParameter.Instance[] TypeParameterInstances { get; } = Array.Empty<TypeParameter.Instance>();
+        public TypeParameter.Instance[] TypeParameterInstances { get; private set; } = Array.Empty<TypeParameter.Instance>();
 
         public override string Name => base.Name +
                                        (TypeParameters.Count == 0
@@ -357,7 +359,7 @@ public bool CanHold(IClass? type)
             }
         }
 
-        public static void InitializePrimitives(RuntimeBase runtimeBase)
+        public static void InitializePrimitives(RuntimeBase vm)
         {
             #region Void Class
             
@@ -449,6 +451,10 @@ public static void InitializePrimitives(RuntimeBase runtimeBase)
                 }
             });
             var decremental = new DummyMethod(VoidType, "decremental", MemberModifier.Public | MemberModifier.Final, NumericByteType);
+            
+            // iterable methods
+            var iterator = new DummyMethod(IterableType, "iterator", MemberModifier.Public | MemberModifier.Abstract, 
+                IteratorType.CreateInstance(vm, IterableType, IterableType.TypeParameters[0]));
 
             AddToClass(RangeType, toString);
             AddToClass(RangeType, equals);
@@ -458,6 +464,32 @@ public static void InitializePrimitives(RuntimeBase runtimeBase)
             AddToClass(RangeType, accumulate);
             AddToClass(RangeType, decremental);
             AddToClass(RangeType, getType);
+            AddToClass(RangeType, iterator);
+            RangeType.Interfaces.Add(IterableType.CreateInstance(vm, RangeType, NumericIntType));
+            
+            #endregion
+
+            #region Iterator Class
+            
+            var current = new DummyMethod(IteratorType, "current", MemberModifier.Public | MemberModifier.Abstract, IteratorType.TypeParameters[0]);
+            var next = new DummyMethod(IteratorType, "next", MemberModifier.Public | MemberModifier.Abstract, IteratorType.TypeParameters[0]);
+            var hasNext = new DummyMethod(IteratorType, "hasNext", MemberModifier.Public | MemberModifier.Abstract, NumericByteType);
+
+            AddToClass(IteratorType, toString);
+            AddToClass(IteratorType, equals);
+            AddToClass(IteratorType, getType);
+            AddToClass(IteratorType, current);
+            AddToClass(IteratorType, next);
+            AddToClass(IteratorType, hasNext);
+            
+            #endregion
+
+            #region Iterable Class
+
+            AddToClass(IterableType, toString);
+            AddToClass(IterableType, equals);
+            AddToClass(IterableType, getType);
+            AddToClass(IterableType, iterator);
             
             #endregion
 
@@ -543,6 +575,15 @@ public Instance(TypeParameter typeParameter, ITypeInfo targetType)
             public string Name => TypeParameter.Name;
             public string FullName => TypeParameter.FullName;
             public List<ITypeInfo> TypeParameters { get; } = new();
+
+            public IClassInstance ResolveType(RuntimeBase vm, IClassInstance usingClass)
+            {
+                if (usingClass.TypeParameterInstances.Length == 0 
+                    || usingClass.TypeParameterInstances.All(x => x.TypeParameter.Name != TypeParameter.Name))
+                    throw new ArgumentException("Invalid resolver class");
+                return vm.FindType(usingClass.TypeParameterInstances
+                    .First(x => x.TypeParameter.Name == TypeParameter.Name).TargetType.FullName)!;
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/kscr-lib/Bytecode/Method.cs b/kscr-lib/Bytecode/Method.cs
index 6e77ac7..09be818 100644
--- a/kscr-lib/Bytecode/Method.cs
+++ b/kscr-lib/Bytecode/Method.cs
@@ -115,7 +115,8 @@ public override void Write(Stream stream)
             stream.Write(BitConverter.GetBytes(Parameters.Count));
             foreach (var parameter in Parameters)
                 parameter.Write(stream);
-            Body.Write(stream);
+            if (!this.IsAbstract())
+                Body.Write(stream);
         }
 
         public override void Load(RuntimeBase vm, byte[] data, ref int i)
@@ -129,8 +130,11 @@ public override void Load(RuntimeBase vm, byte[] data, ref int i)
             Parameters.Clear();
             for (; len > 0; len--)
                 Parameters.Add(MethodParameter.Read(vm, data, ref i));
-            Body = new ExecutableCode();
-            Body.Load(vm, data, ref i);
+            if (!this.IsAbstract())
+            {
+                Body = new ExecutableCode();
+                Body.Load(vm, data, ref i);
+            }
         }
 
         public new static Method Read(RuntimeBase vm, Class parent, byte[] data, ref int i)
diff --git a/kscr-lib/Bytecode/Package.cs b/kscr-lib/Bytecode/Package.cs
index c272394..417c0ea 100644
--- a/kscr-lib/Bytecode/Package.cs
+++ b/kscr-lib/Bytecode/Package.cs
@@ -32,13 +32,17 @@ public void Write(DirectoryInfo dir, ClassInfo[]? names = null)
         {
             names ??= Array.Empty<ClassInfo>();
             foreach (var member in Members.Values)
-                if (!names.Any(name => name.FullName.StartsWith(member.FullName)))
+                if (!names.Any(name => name.FullName.StartsWith(member.FullName.Contains("<") 
+                        ? member.FullName.Substring(0, member.FullName.IndexOf('<'))
+                        : member.FullName)))
                     // ReSharper disable once RedundantJumpStatement
                     continue;
                 else if (member is Package pkg)
                     pkg.Write(dir.CreateSubdirectory(member.Name), names);
                 else if (member is Class cls)
-                    cls.Write(new FileInfo(Path.Combine(dir.FullName, member.Name + ".kbin")));
+                    cls.Write(new FileInfo(Path.Combine(dir.FullName, (member.Name.Contains("<")
+                        ? member.Name.Substring(0, member.Name.IndexOf("<", StringComparison.Ordinal)) 
+                        : member.Name)  + ".kbin")));
                 else throw new NotSupportedException("Member is of unsupported type: " + member.GetType());
         }
 
diff --git a/kscr-lib/Bytecode/Statement.cs b/kscr-lib/Bytecode/Statement.cs
index 604ea69..64a20e4 100644
--- a/kscr-lib/Bytecode/Statement.cs
+++ b/kscr-lib/Bytecode/Statement.cs
@@ -248,20 +248,22 @@ public virtual State Evaluate(RuntimeBase vm, ref ObjectRef rev)
                         return _rev;
                     });
                     break;
-                case (StatementComponentType.Code, BytecodeType.StmtForN):
-                    vm.Stack.StepInside(vm, SourcefilePosition, "forn", ref rev, _rev =>
+                case (StatementComponentType.Code, BytecodeType.StmtForEach):
+                    vm.Stack.StepInside(vm, SourcefilePosition, "foreach", ref rev, _rev =>
                     {
                         state = SubStatement!.Evaluate(vm, ref buf!);
                         if (state != State.Normal)
                             return _rev;
-                        var range = (buf.Value as Range)!;
-                        var n = vm[VariableContext.Local, Arg] = new ObjectRef(Class.NumericIntType);
-                        n.Value = range.start(vm).Value;
-                        do
+                        var iterable = (buf.Value as IObject)!;
+                        var iter = iterable.Invoke(vm, "iterator", ref buf!);
+                        var iterator = iter.Value;
+                        var n = vm[VariableContext.Local, Arg] = new ObjectRef(iterator.Type.TypeParameterInstances[0].ResolveType(vm, iterator.Type));
+                        while (state == State.Normal && iterator.Invoke(vm, "hasNext", ref n).ToBool())
                         {
+                            n.Value = iterator.Invoke(vm, "next", ref iter).Value;
+                            iter.Value = iterator;
                             state = InnerCode!.Evaluate(vm, ref _rev);
-                            n.Value = range.accumulate(vm, (n.Value as Numeric)!).Value;
-                        } while (state == State.Normal && range.test(vm, (n.Value as Numeric)!).ToBool());
+                        }
 
                         vm[VariableContext.Local, Arg] = null;
                         return _rev;
diff --git a/kscr-lib/Core/Range.cs b/kscr-lib/Core/Range.cs
index d2bbff8..cb81b00 100644
--- a/kscr-lib/Core/Range.cs
+++ b/kscr-lib/Core/Range.cs
@@ -43,6 +43,8 @@ private Range(RuntimeBase vm, int start, int end)
                     return Start == other.Start && End == other.End ? vm.ConstantTrue : vm.ConstantFalse;
                 case "getType":
                     return Type.SelfRef;
+                case "iterator":
+                    return vm.PutObject(VariableContext.Local, "iterator", new RangeIterator(vm, this));
                 case "start": // get first value
                     return start(vm);
                 case "end": // get last value
@@ -61,7 +63,41 @@ private Range(RuntimeBase vm, int start, int end)
 
             throw new NotImplementedException();
         }
-        
+
+        private class RangeIterator : IObject
+        {
+            private readonly Range _range;
+            private ObjectRef? _n;
+
+            public RangeIterator(RuntimeBase vm, Range range)
+            {
+                _range = range;
+                ObjectId = vm.NextObjId(ToString(0));
+                Type = Class.IteratorType.CreateInstance(vm, Class.NumericIntType);
+            }
+
+            public long ObjectId { get; }
+            public IClassInstance Type { get; }
+
+            public string ToString(short variant) => "range-iterator:" + _range;
+
+            public ObjectRef? Invoke(RuntimeBase vm, string member, ref ObjectRef? rev, params IObject?[] args)
+            {
+                switch (member)
+                {
+                    case "current":
+                        return _n ?? vm.ConstantVoid;
+                    case "next":
+                        return _n = _n == null ? _range.start(vm) : _range.accumulate(vm, (_n.Value as Numeric)!);
+                    case "hasNext":
+                        return _n == null ? vm.ConstantTrue
+                            : _range.test(vm, (_range.accumulate(vm, (_n.Value as Numeric)!).Value as Numeric)!);
+                    default:
+                        throw new InvalidOperationException();
+                }
+            }
+        }
+
         public ObjectRef start(RuntimeBase vm) => Numeric.Constant(vm, Start);
         public ObjectRef end(RuntimeBase vm) => Numeric.Constant(vm, End);
         public ObjectRef test(RuntimeBase vm, Numeric n) => (Decremental ? n.IntValue > End : n.IntValue < End) ? vm.ConstantTrue : vm.ConstantFalse;
diff --git a/kscr-lib/Model/BytecodePacket.cs b/kscr-lib/Model/BytecodePacket.cs
index c96fc56..59c8706 100644
--- a/kscr-lib/Model/BytecodePacket.cs
+++ b/kscr-lib/Model/BytecodePacket.cs
@@ -38,8 +38,7 @@ public enum BytecodeType : uint
         StmtDo = 0x0021_0000 | Statement,
         StmtWhile = 0x0022_0000 | Statement,
         StmtFor = 0x0041_0000 | Statement,
-        StmtForN = 0x0042_0000 | Statement,
-        StmtForEach = 0x0044_0000 | Statement,
+        StmtForEach = 0x00422_0000 | Statement,
 
         StdioExpression = 0x0200_0000,
         ParameterExpression = 0x0100_0000,
diff --git a/kscr-lib/Model/ICompiler.cs b/kscr-lib/Model/ICompiler.cs
index 92fa29a..49ec33f 100644
--- a/kscr-lib/Model/ICompiler.cs
+++ b/kscr-lib/Model/ICompiler.cs
@@ -240,7 +240,7 @@ public void Clear()
             return vm.FindType(name, Package);
         }
 
-        public ITypeInfo FindFullTypeInfo(RuntimeBase vm, bool _rec = false)
+        public ITypeInfo FindTypeInfo(RuntimeBase vm, bool _rec = false)
         {
             var type = FindType(vm, Token.Arg!);
             if (type?.Name == Token.Arg && NextToken?.Type != TokenType.ParDiamondOpen)
@@ -256,7 +256,7 @@ public ITypeInfo FindFullTypeInfo(RuntimeBase vm, bool _rec = false)
                 do
                 {
                     TokenIndex += 2;
-                    args.Add(FindFullTypeInfo(vm, true));
+                    args.Add(FindTypeInfo(vm, true));
                 } while (NextToken?.Type == TokenType.Comma);
 
                 TokenIndex += 1;
diff --git a/kscr-lib/Model/ITokenizer.cs b/kscr-lib/Model/ITokenizer.cs
index be4d24e..39a01ee 100644
--- a/kscr-lib/Model/ITokenizer.cs
+++ b/kscr-lib/Model/ITokenizer.cs
@@ -69,7 +69,6 @@ public enum TokenType : uint
         Do = 0x0120_80,
         While = 0x0120_81,
         For = 0x0120_82,
-        ForN = 0x0120_84,
         ForEach = 0x0120_88,
         Switch = 0x0120_F4,
         Case = 0x0120_F0,
@@ -167,7 +166,6 @@ public static string String(this IToken token)
                 TokenType.Do => "do",
                 TokenType.While => "while",
                 TokenType.For => "for",
-                TokenType.ForN => "forn",
                 TokenType.ForEach => "foreach",
                 TokenType.Switch => "foreach",
                 TokenType.Case => "foreach",
diff --git a/kscr-lib/RuntimeBase.cs b/kscr-lib/RuntimeBase.cs
index 393de52..7274fbe 100644
--- a/kscr-lib/RuntimeBase.cs
+++ b/kscr-lib/RuntimeBase.cs
@@ -48,6 +48,8 @@ public void Initialize()
             Class.ArrayType.Initialize(this);
             Class.StringType.Initialize(this);
             Class.RangeType.Initialize(this);
+            Class.IterableType.Initialize(this);
+            Class.IteratorType.Initialize(this);
             Class.ThrowableType.Initialize(this);
             Class.NumericType.Initialize(this);
             Class.NumericByteType.Initialize(this);
diff --git a/kscr-runtime/Program.cs b/kscr-runtime/Program.cs
index 0aa79b3..b6c520d 100644
--- a/kscr-runtime/Program.cs
+++ b/kscr-runtime/Program.cs
@@ -39,7 +39,8 @@ private static int Main(string[] args)
                     RuntimeBase.ConfirmExit = cmd.Confirm;
                     RuntimeBase.DebugMode = cmd.Debug;
                     // load std package
-                    Package.ReadAll(VM, new DirectoryInfo(StdPackageLocation));
+                    if (!cmd.System)
+                        Package.ReadAll(VM, new DirectoryInfo(StdPackageLocation));
                     // load additional classpath packages
                     foreach (var classpath in cmd.Classpath.Where(dir => dir.Exists))
                         Package.ReadAll(VM, classpath);