diff --git a/src/actions/vstudio/vs2005_csproj.lua b/src/actions/vstudio/vs2005_csproj.lua
index e35e7814..d27196d0 100644
--- a/src/actions/vstudio/vs2005_csproj.lua
+++ b/src/actions/vstudio/vs2005_csproj.lua
@@ -1,13 +1,22 @@
 --
 -- vs2005_csproj.lua
 -- Generate a Visual Studio 2005/2008 C# project.
--- Copyright (c) 2009 Jason Perkins and the Premake project
+-- Copyright (c) 2009-2010 Jason Perkins and the Premake project
 --
 
-	--
-	-- Figure out what elements a particular source code file need in its item
-	-- block, based on its build action and any related files in the project.
-	-- 
+--
+-- Set up namespaces
+--
+
+	premake.vstudio.cs2005 = { }
+	local vstudio = premake.vstudio
+	local cs2005  = premake.vstudio.cs2005
+
+
+--
+-- Figure out what elements a particular source code file need in its item
+-- block, based on its build action and any related files in the project.
+-- 
 	
 	local function getelements(prj, action, fname)
 	
@@ -61,6 +70,32 @@
 	end
 
 
+--
+-- Write the opening <Project> element and project level <PropertyGroup> block.
+--
+
+	function cs2005.projectheader(prj)
+		local vsversion, toolversion
+		if _ACTION == "vs2005" then
+			vsversion   = "8.0.50727"
+			toolversion = nil
+		elseif _ACTION == "vs2008" then
+			vsversion   = "9.0.21022"
+			toolversion = "3.5"
+		end
+		
+		if toolversion then
+			_p('<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="%s">', toolversion)
+		else
+			_p('<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">')
+		end
+	end
+
+
+--
+-- The main function: write the project file.
+--
+
 	function premake.vs2005_csproj(prj)
 		io.eol = "\r\n"
 
diff --git a/src/base/api.lua b/src/base/api.lua
index 5601f230..83a4d886 100644
--- a/src/base/api.lua
+++ b/src/base/api.lua
@@ -102,6 +102,20 @@
 			}
 		},
 		
+		framework =
+		{
+			kind = "string",
+			scope = "container",
+			allowed = {
+				"1.0",
+				"1.1",
+				"2.0",
+				"3.0",
+				"3.5",
+				"4.0"
+			}
+		},
+		
 		imageoptions =
 		{
 			kind  = "list",
diff --git a/tests/actions/vstudio/test_vs2005_csproj.lua b/tests/actions/vstudio/test_vs2005_csproj.lua
new file mode 100644
index 00000000..b300cf56
--- /dev/null
+++ b/tests/actions/vstudio/test_vs2005_csproj.lua
@@ -0,0 +1,55 @@
+--
+-- tests/actions/test_vs2005_csproj.lua
+-- Automated test suite for Visual Studio 2005-2008 C# project generation.
+-- Copyright (c) 2010 Jason Perkins and the Premake project
+--
+
+	T.vs2005_csproj = { }
+	local suite = T.vs2005_csproj
+	local cs2005 = premake.vstudio.cs2005
+
+--
+-- Configure a solution for testing
+--
+
+	local sln, prj
+	function suite.setup()
+		_ACTION = "vs2005"
+
+		sln = solution "MySolution"
+		configurations { "Debug", "Release" }
+		platforms {}
+		
+		prj = project "MyProject"
+		language "C#"
+		kind "ConsoleApp"
+		uuid "AE61726D-187C-E440-BD07-2556188A6565"		
+	end
+
+	local function prepare()
+		io.capture()
+		premake.buildconfigs()
+	end
+
+
+--
+-- Project header tests
+--
+
+	function suite.projectheader_OnVs2005()
+		_ACTION = "vs2005"
+		prepare()
+		cs2005.projectheader(prj)
+		test.capture [[
+<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+		]]
+	end
+
+	function suite.projectheader_OnVs2008()
+		_ACTION = "vs2008"
+		prepare()
+		cs2005.projectheader(prj)
+		test.capture [[
+<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="3.5">
+		]]
+	end
diff --git a/tests/premake4.lua b/tests/premake4.lua
index 2f03c6ac..ff89d37a 100644
--- a/tests/premake4.lua
+++ b/tests/premake4.lua
@@ -63,6 +63,7 @@
 	dofile("test_vs2003_sln.lua")
 	dofile("test_vs2005_sln.lua")
 	dofile("test_vs2008_sln.lua")
+	dofile("actions/vstudio/test_vs2005_csproj.lua")
 	dofile("actions/vstudio/test_vs200x_vcproj.lua")
 
 	-- Xcode tests