Index: scripts/Templates/NodeImpl.cs
===================================================================
--- scripts/Templates/NodeImpl.cs	(revision 3325)
+++ scripts/Templates/NodeImpl.cs	(working copy)
@@ -6,8 +6,8 @@
 
 %>namespace Boo.Lang.Compiler.Ast
 {	
+	using System;
 	using System.Collections;
-	using System.Runtime.Serialization;
 	
 	[System.Serializable]
 	public ${abstractClass}partial class ${node.Name} : ${join(node.BaseTypes, ', ')}
@@ -119,7 +119,7 @@
 		[System.CodeDom.Compiler.GeneratedCodeAttribute("astgen.boo", "1")]
 		override public object Clone()
 		{
-			${node.Name} clone = (${node.Name})FormatterServices.GetUninitializedObject(typeof(${node.Name}));
+			${node.Name} clone = (${node.Name})Activator.CreateInstance(typeof(${node.Name}));
 			clone._lexicalInfo = _lexicalInfo;
 			clone._endSourceLocation = _endSourceLocation;
 			clone._documentation = _documentation;
Index: src/Boo.Lang.CodeDom/AssemblyInfo.boo
===================================================================
--- src/Boo.Lang.CodeDom/AssemblyInfo.boo	(revision 3325)
+++ src/Boo.Lang.CodeDom/AssemblyInfo.boo	(working copy)
@@ -31,8 +31,8 @@
 // Ian MacLean (original C# version)
 
 import System.Reflection;
+import System.Security;
 import System.Security.Permissions;
-
 [assembly: ReflectionPermission(SecurityAction.RequestMinimum,
 								ReflectionEmit: true,
 								TypeInformation: true)]
@@ -44,4 +44,4 @@
 [assembly: AssemblyCulture("")]
 [assembly: AssemblyDelaySign(false)]
 [assembly: AssemblyVersion("2.0.9.1")]
-
+[assembly: AllowPartiallyTrustedCallers]
Index: src/Boo.Lang.Compiler/AssemblyInfo.cs
===================================================================
--- src/Boo.Lang.Compiler/AssemblyInfo.cs	(revision 3325)
+++ src/Boo.Lang.Compiler/AssemblyInfo.cs	(working copy)
@@ -27,6 +27,7 @@
 #endregion
 
 using System.Reflection;
+using System.Security;
 using System.Security.Permissions;
 
 [assembly: AssemblyTitle("boo - an extensible programming language for the CLI")]
@@ -39,4 +40,4 @@
 [assembly: AssemblyCulture("")]
 [assembly: AssemblyVersion("2.0.9.1")]
 [assembly: AssemblyDelaySign(false)]
-
+[assembly: AllowPartiallyTrustedCallers]
Index: src/Boo.Lang.Compiler/Boo.Lang.Compiler-VS2005.csproj
===================================================================
--- src/Boo.Lang.Compiler/Boo.Lang.Compiler-VS2005.csproj	(revision 3325)
+++ src/Boo.Lang.Compiler/Boo.Lang.Compiler-VS2005.csproj	(working copy)
@@ -88,6 +88,7 @@
     <Compile Include="ICompilerStep.cs" />
     <Compile Include="LexicalInfoPreservingGeneratorMacro.cs" />
     <Compile Include="LexicalInfoPreservingMacro.cs" />
+    <Compile Include="MediumTrust.cs" />
     <Compile Include="My.cs" />
     <Compile Include="Ast\ArrayLiteralExpression.cs" />
     <Compile Include="Ast\ArrayTypeReference.cs" />
Index: src/Boo.Lang.Compiler/Boo.Lang.Compiler-VS2008.csproj
===================================================================
--- src/Boo.Lang.Compiler/Boo.Lang.Compiler-VS2008.csproj	(revision 3325)
+++ src/Boo.Lang.Compiler/Boo.Lang.Compiler-VS2008.csproj	(working copy)
@@ -109,6 +109,7 @@
     <Compile Include="ICompilerStep.cs" />
     <Compile Include="LexicalInfoPreservingGeneratorMacro.cs" />
     <Compile Include="LexicalInfoPreservingMacro.cs" />
+    <Compile Include="MediumTrust.cs" />
     <Compile Include="My.cs" />
     <Compile Include="Ast\ArrayLiteralExpression.cs" />
     <Compile Include="Ast\ArrayTypeReference.cs" />
Index: src/Boo.Lang.Compiler/Boo.Lang.Compiler.mdp
===================================================================
--- src/Boo.Lang.Compiler/Boo.Lang.Compiler.mdp	(revision 3325)
+++ src/Boo.Lang.Compiler/Boo.Lang.Compiler.mdp	(working copy)
@@ -45,6 +45,7 @@
     <File name="ICompilerStep.cs" buildaction="Compile" subtype="Code" />
     <File name="LexicalInfoPreservingGeneratorMacro.cs" buildaction="Compile" subtype="Code" />
     <File name="LexicalInfoPreservingMacro.cs" buildaction="Compile" subtype="Code" />
+    <File name="MediumTrust.cs" buildaction="Compile" subtype="Code" />
     <File name="My.cs" buildaction="Compile" subtype="Code" />
     <File name="Ast/ArrayLiteralExpression.cs" buildaction="Compile" subtype="Code" />
     <File name="Ast/ArrayTypeReference.cs" buildaction="Compile" subtype="Code" />
Index: src/Boo.Lang.Compiler/CompilerParameters.cs
===================================================================
--- src/Boo.Lang.Compiler/CompilerParameters.cs	(revision 3325)
+++ src/Boo.Lang.Compiler/CompilerParameters.cs	(working copy)
@@ -34,6 +34,8 @@
 using System.Diagnostics;
 using System.IO;
 using System.Reflection;
+using System.Security;
+using System.Security.Permissions;
 using System.Text.RegularExpressions;
 using Boo.Lang.Compiler.Ast;
 using Boo.Lang.Compiler.TypeSystem;
@@ -113,10 +115,13 @@
 		public CompilerParameters(IReflectionTypeSystemProvider reflectionProvider, bool loadDefaultReferences)
 		{
 			_libpaths = new ArrayList();
-			_systemDir = GetSystemDir();
-			_libpaths.Add(_systemDir);
-			_libpaths.Add(Directory.GetCurrentDirectory());
-
+			_hasDiscoveryPermission = MediumTrust.HasDiscoveryPermission();
+			if (_hasDiscoveryPermission)
+			{
+				_systemDir = GetSystemDir();
+				_libpaths.Add(_systemDir);
+				_libpaths.Add(Directory.GetCurrentDirectory());
+			}
 			_pipeline = null;
 			_input = new CompilerInputCollection();
 			_resources = new CompilerResourceCollection();
@@ -131,7 +136,7 @@
 			_generateInMemory = true;
 			_StdLib = true;
 
-			if (null != Environment.GetEnvironmentVariable("TRACE"))
+			if (MediumTrust.HasEnvironmentPermission() && null != Environment.GetEnvironmentVariable("TRACE"))
 				EnableTraceSwitch();
 
 			_delaySign = false;
@@ -162,7 +167,9 @@
 
 			//boo.lang.extensions.dll
 			//try loading extensions next to Boo.Lang (in the same directory)
-			string tentative = Path.Combine(Path.GetDirectoryName(_booAssembly.Location) , "Boo.Lang.Extensions.dll");
+			string tentative = "Boo.Lang.Extensions.dll";
+			if (_hasDiscoveryPermission)
+				tentative = Path.Combine(Path.GetDirectoryName(_booAssembly.Location), tentative);
 			ICompileUnit extensionsAssembly = LoadAssembly(tentative, false);
 			if(extensionsAssembly == null)//if failed, try loading from the gac
 				extensionsAssembly = LoadAssembly("Boo.Lang.Extensions", false);
@@ -705,6 +712,7 @@
 		bool _warnAsError = false;
 		Util.Set<string> _disabledWarnings = new Util.Set<string>();
 		Util.Set<string> _promotedWarnings = new Util.Set<string>();
+		private bool _hasDiscoveryPermission;
 
 		public bool NoWarn
 		{
Index: src/Boo.Lang.Compiler/Pipelines/Parse.cs
===================================================================
--- src/Boo.Lang.Compiler/Pipelines/Parse.cs	(revision 3325)
+++ src/Boo.Lang.Compiler/Pipelines/Parse.cs	(working copy)
@@ -48,7 +48,7 @@
 		static Assembly FindParserAssembly()
 		{
 			Assembly thisAssembly = typeof(Parse).Assembly;
-			string thisLocation = thisAssembly.Location;
+			string thisLocation = MediumTrust.HasDiscoveryPermission() ?  thisAssembly.Location : "";
 			string parserLocation = thisLocation.EndsWith("Boo.Lang.Compiler.dll")
                 	? thisLocation.Substring(0, thisLocation.Length - "Boo.Lang.Compiler.dll".Length) + "Boo.Lang.Parser.dll"
                 	: "";
Index: src/Boo.Lang.Compiler/Steps/EmitAssembly.cs
===================================================================
--- src/Boo.Lang.Compiler/Steps/EmitAssembly.cs	(revision 3325)
+++ src/Boo.Lang.Compiler/Steps/EmitAssembly.cs	(working copy)
@@ -407,6 +407,19 @@
 			
 			public void Run()
 			{
+				if (MediumTrust.HasAppDomainPermission())
+					RunInFullTrust();
+				else
+				{
+					CreateTypes();
+				}
+			}
+			private void RunInMediumTrust()
+			{
+				CreateTypes();
+			}
+			private void RunInFullTrust()
+			{
 				ResolveEventHandler resolveHandler = new ResolveEventHandler(OnTypeResolve);
 				AppDomain current = Thread.GetDomain();
 				
@@ -418,9 +431,9 @@
 				finally
 				{
 					current.TypeResolve -= resolveHandler;
-				}
+				}
 			}
-			
+
 			void CreateTypes()
 			{
 				foreach (TypeMember type in _types)
Index: src/Boo.Lang.Compiler/TypeSystem/Reflection/AssemblyReference.cs
===================================================================
--- src/Boo.Lang.Compiler/TypeSystem/Reflection/AssemblyReference.cs	(revision 3325)
+++ src/Boo.Lang.Compiler/TypeSystem/Reflection/AssemblyReference.cs	(working copy)
@@ -26,6 +26,8 @@
 // THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endregion
 
+using System.Reflection;
+
 namespace Boo.Lang.Compiler.TypeSystem.Reflection
 {
 	using System;
@@ -46,7 +48,7 @@
 		
 		public string Name
 		{
-			get { return _assembly.GetName().Name; }
+			get { return new AssemblyName(_assembly.FullName).Name; }
 		}
 		
 		public string FullName
Index: src/Boo.Lang.Extensions/AssemblyInfo.boo
===================================================================
--- src/Boo.Lang.Extensions/AssemblyInfo.boo	(revision 3325)
+++ src/Boo.Lang.Extensions/AssemblyInfo.boo	(working copy)
@@ -28,6 +28,7 @@
 
 import System.Reflection;
 import System.Security.Permissions;
+import System.Security;
 
 [assembly: ReflectionPermission(SecurityAction.RequestMinimum,
 								ReflectionEmit: true)]
@@ -40,4 +41,5 @@
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]
 [assembly: AssemblyVersion("2.0.9.1")]
+[assembly: AllowPartiallyTrustedCallers]
 
Index: src/Boo.Lang.Interpreter/AssemblyInfo.boo
===================================================================
--- src/Boo.Lang.Interpreter/AssemblyInfo.boo	(revision 3325)
+++ src/Boo.Lang.Interpreter/AssemblyInfo.boo	(working copy)
@@ -27,6 +27,7 @@
 #endregion
 
 import System.Reflection
+import System.Security
 
 [assembly: AssemblyTitle("Boo Language Interpreter Library")]
 [assembly: AssemblyDescription("")]
@@ -37,4 +38,4 @@
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]
 [assembly: AssemblyVersion("2.0.9.1")]
-
+[assembly: AllowPartiallyTrustedCallers]
Index: src/Boo.Lang.Parser/AssemblyInfo.cs
===================================================================
--- src/Boo.Lang.Parser/AssemblyInfo.cs	(revision 3325)
+++ src/Boo.Lang.Parser/AssemblyInfo.cs	(working copy)
@@ -27,6 +27,7 @@
 #endregion
 
 using System.Reflection;
+using System.Security;
 
 [assembly: AssemblyTitle("boo antlr based parser")]
 [assembly: AssemblyDescription("")]
@@ -38,4 +39,5 @@
 [assembly: AssemblyCulture("")]
 [assembly: AssemblyVersion("2.0.9.1")]
 [assembly: AssemblyDelaySign(false)]
+[assembly: AllowPartiallyTrustedCallers]
 
Index: src/Boo.Lang.PatternMatching/AssemblyInfo.boo
===================================================================
--- src/Boo.Lang.PatternMatching/AssemblyInfo.boo	(revision 3325)
+++ src/Boo.Lang.PatternMatching/AssemblyInfo.boo	(working copy)
@@ -27,6 +27,7 @@
 #endregion
 
 import System.Reflection
+import System.Security
 
 [assembly: AssemblyTitle("Boo Pattern Matching Library")]
 [assembly: AssemblyDescription("")]
@@ -37,4 +38,4 @@
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]
 [assembly: AssemblyVersion("2.0.9.1")]
-
+[assembly: AllowPartiallyTrustedCallers]
Index: src/Boo.Lang.Useful/AssemblyInfo.boo
===================================================================
--- src/Boo.Lang.Useful/AssemblyInfo.boo	(revision 3325)
+++ src/Boo.Lang.Useful/AssemblyInfo.boo	(working copy)
@@ -27,6 +27,7 @@
 #endregion
 
 import System.Reflection
+import System.Security
 
 [assembly: AssemblyTitle("Boo Language Useful Library")]
 [assembly: AssemblyDescription("")]
@@ -37,4 +38,4 @@
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]
 [assembly: AssemblyVersion("2.0.9.1")]
-
+[assembly: AllowPartiallyTrustedCallers]
Index: src/Boo.Lang/AssemblyInfo.cs
===================================================================
--- src/Boo.Lang/AssemblyInfo.cs	(revision 3325)
+++ src/Boo.Lang/AssemblyInfo.cs	(working copy)
@@ -26,7 +26,8 @@
 // THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endregion
 
-using System.Reflection;
+using System.Reflection;
+using System.Security;
 
 [assembly: AssemblyTitle("boo - an extensible programming language for the CLI")]
 [assembly: AssemblyDescription("")]
@@ -43,4 +44,5 @@
 #endif
 [assembly: AssemblyKeyName("")]
 
-[assembly: System.Resources.NeutralResourcesLanguage("en")]
+[assembly: System.Resources.NeutralResourcesLanguage("en")]
+[assembly: AllowPartiallyTrustedCallers]
\ No newline at end of file
Index: src/booc/AssemblyInfo.cs
===================================================================
--- src/booc/AssemblyInfo.cs	(revision 3325)
+++ src/booc/AssemblyInfo.cs	(working copy)
@@ -27,6 +27,7 @@
 #endregion
 
 using System.Reflection;
+using System.Security;
 
 [assembly: AssemblyTitle("boo compiler")]
 [assembly: AssemblyDescription("")]
@@ -38,3 +39,4 @@
 [assembly: AssemblyCulture("")]
 [assembly: AssemblyVersion("2.0.9.1")]
 [assembly: AssemblyDelaySign(false)]
+[assembly: AllowPartiallyTrustedCallers]
\ No newline at end of file
Index: tests/BooCompiler.Tests/BooCompiler.Tests-VS2005.csproj
===================================================================
--- tests/BooCompiler.Tests/BooCompiler.Tests-VS2005.csproj	(revision 3325)
+++ tests/BooCompiler.Tests/BooCompiler.Tests-VS2005.csproj	(working copy)
@@ -103,6 +103,8 @@
     <Compile Include="SupportingClasses.cs" />
     <Compile Include="SystemDrawingPoint.cs" />
     <Compile Include="TypesIntegrationTestFixture.cs" />
+    <Compile Include="UnsafeErrorsTestFixture.cs" />
+    <Compile Include="UnsafeTestFixture.cs" />
     <Compile Include="Pipeline\AllParametersRequiredAttribute.cs" />
     <Compile Include="Pipeline\ViewStateAttribute.cs" />
     <Compile Include="TypeSystem\AbstractTypeSystemTest.cs" />
Index: tests/BooCompiler.Tests/BooCompiler.Tests-VS2008.csproj
===================================================================
--- tests/BooCompiler.Tests/BooCompiler.Tests-VS2008.csproj	(revision 3325)
+++ tests/BooCompiler.Tests/BooCompiler.Tests-VS2008.csproj	(working copy)
@@ -79,6 +79,10 @@
       <SpecificVersion>False</SpecificVersion>
       <HintPath>..\..\build\Boo.Lang.Extensions.dll</HintPath>
     </Reference>
+    <Reference Include="Boo.Lang.PatternMatching, Version=2.0.9.1, Culture=neutral, PublicKeyToken=32c39770e9a21a67, processorArchitecture=MSIL">
+      <SpecificVersion>False</SpecificVersion>
+      <HintPath>..\..\bin\Boo.Lang.PatternMatching.dll</HintPath>
+    </Reference>
     <Reference Include="nunit.framework" />
     <Reference Include="System" />
     <Reference Include="System.Data" />
@@ -120,6 +124,8 @@
     <Compile Include="SupportingClasses.cs" />
     <Compile Include="SystemDrawingPoint.cs" />
     <Compile Include="TypesIntegrationTestFixture.cs" />
+    <Compile Include="UnsafeErrorsTestFixture.cs" />
+    <Compile Include="UnsafeTestFixture.cs" />
     <Compile Include="Pipeline\AllParametersRequiredAttribute.cs" />
     <Compile Include="Pipeline\ViewStateAttribute.cs" />
     <Compile Include="TypeSystem\AbstractTypeSystemTest.cs" />