diff --git a/GUI/GuiUtils.cs b/GUI/GuiUtils.cs
index 7b0eb65d0..5b33b6080 100644
--- a/GUI/GuiUtils.cs
+++ b/GUI/GuiUtils.cs
@@ -22,6 +22,9 @@ using System.Windows.Forms;
 
 namespace MCGalaxy.Gui 
 {
+    // NET 2.0 doesn't have Action delegate defined
+    public delegate void UIAction();
+	
     /// <summary> Shortcuts for MessageBox.Show </summary>
     public static class Popup 
     {
diff --git a/GUI/PropertyWindow/PropertyWindow.cs b/GUI/PropertyWindow/PropertyWindow.cs
index f68f02ed6..b5ad679e1 100644
--- a/GUI/PropertyWindow/PropertyWindow.cs
+++ b/GUI/PropertyWindow/PropertyWindow.cs
@@ -32,7 +32,7 @@ namespace MCGalaxy.Gui
             propsZG.SelectedObject = zsSettings;
         }
         
-        public void RunOnUI_Async(Action act) { BeginInvoke(act); }
+        public void RunOnUI_Async(UIAction act) { BeginInvoke(act); }
 
         void PropertyWindow_Load(object sender, EventArgs e) {
             // try to use same icon as main window
diff --git a/GUI/Window/Window.cs b/GUI/Window/Window.cs
index 61b8411a0..4f1831f77 100644
--- a/GUI/Window/Window.cs
+++ b/GUI/Window/Window.cs
@@ -28,8 +28,10 @@ using MCGalaxy.Generator;
 using MCGalaxy.Gui.Popups;
 using MCGalaxy.Tasks;
 
-namespace MCGalaxy.Gui {
-    public partial class Window : Form {
+namespace MCGalaxy.Gui 
+{
+    public partial class Window : Form 
+    {
         // for cross thread use
         delegate void StringCallback(string s);
         delegate void PlayerListCallback(List<Player> players);
@@ -237,7 +239,7 @@ Trying to mix two versions is unsupported - you may experience issues";
             RunOnUI_Async(() => main_btnProps.Enabled = true);
         }
 
-        public void RunOnUI_Async(Action act) { BeginInvoke(act); }
+        public void RunOnUI_Async(UIAction act) { BeginInvoke(act); }
         
         void Player_PlayerConnect(Player p) {
             RunOnUI_Async(() => {
diff --git a/MCGalaxy/Network/Listeners.cs b/MCGalaxy/Network/Listeners.cs
index ac945dcff..88f3993e9 100644
--- a/MCGalaxy/Network/Listeners.cs
+++ b/MCGalaxy/Network/Listeners.cs
@@ -115,7 +115,7 @@ namespace MCGalaxy.Network
         static void AcceptCallback(IAsyncResult result) {
             if (Server.shuttingDown) return;
             TcpListen listen = (TcpListen)result.AsyncState;
-            TcpSocket s = null;
+            INetSocket s = null;
             
             try {
                 Socket raw  = listen.socket.EndAccept(result);
@@ -126,7 +126,13 @@ namespace MCGalaxy.Network
                     // intentionally non-clean connection close
                     try { raw.Close(); } catch { }
                 } else {
+                    #if NET_20
+                    // TODO better non-hardcoded detection? move to OperatingSystem?
+                    s = Environment.OSVersion.Platform == PlatformID.Win32Windows ? (INetSocket)(new TcpLegacySocket(raw)) : (INetSocket)(new TcpSocket(raw));
+                    #else
                     s = new TcpSocket(raw);
+                    #endif
+                    
                     if (announce) Logger.Log(LogType.UserActivity, s.IP + " connected to the server.");
                     s.Init();
                 }
@@ -139,7 +145,7 @@ namespace MCGalaxy.Network
 
         public override void Close() {
             try {
-        	    Listening = false;
+                Listening = false;
                 if (socket != null) socket.Close();
             } catch (Exception ex) { 
                 Logger.LogError(ex); 
diff --git a/MCGalaxy/Network/Sockets.cs b/MCGalaxy/Network/Sockets.cs
index dac49740b..48a0d3bd3 100644
--- a/MCGalaxy/Network/Sockets.cs
+++ b/MCGalaxy/Network/Sockets.cs
@@ -327,4 +327,135 @@ namespace MCGalaxy.Network
             return IPAddress.IsLoopback(ip) || ip.Equals(ccnetIP);
         }
     }
+    
+    // TODO avoid copying so much of TcpSocket
+    #if NET_20  
+    /// <summary> Backwards compatible socket for older Windows versions where Recv/SendAsync doesn't work </summary>
+    public sealed class TcpLegacySocket : INetSocket 
+    {
+        readonly Socket socket;
+        byte[] recvBuffer = new byte[256];
+        
+        byte[] sendBuffer = new byte[4096];
+        readonly object sendLock = new object();
+        readonly Queue<byte[]> sendQueue = new Queue<byte[]>(64);
+        volatile bool sendInProgress;
+        
+        public TcpLegacySocket(Socket s) { socket = s; }
+        
+        public override void Init() {
+            ReceiveNextAsync();
+        }
+        
+        public override IPAddress IP {
+            get { return SocketUtil.GetIP(socket); }
+        }
+        public override bool LowLatency { set { socket.NoDelay = value; } }
+        
+        
+        static AsyncCallback recvCallback = RecvCallback;
+        void ReceiveNextAsync() {
+            socket.BeginReceive(recvBuffer, 0, recvBuffer.Length, 0, recvCallback, this);
+        }
+        
+        static void RecvCallback(IAsyncResult result) {
+            TcpLegacySocket s = (TcpLegacySocket)result.AsyncState;
+            if (s.Disconnected) return;
+            
+            try {
+                // If received 0, means socket was closed
+                int recvLen = s.socket.EndReceive(result);
+                if (recvLen == 0) { s.Disconnect(); return; }
+                
+                s.HandleReceived(s.recvBuffer, recvLen);
+                if (!s.Disconnected) s.ReceiveNextAsync();
+            } catch (SocketException) {
+                s.Disconnect();
+            } catch (ObjectDisposedException) {
+                // Socket was closed by another thread, mark as disconnected
+            } catch (Exception ex) {
+                Logger.LogError(ex);
+                s.Disconnect();
+            }
+        }
+        
+        
+        static AsyncCallback sendCallback = SendCallback;
+        public override void Send(byte[] buffer, SendFlags flags) {
+            if (Disconnected || !socket.Connected) return;
+
+            // TODO: Low priority sending support
+            try {
+                if ((flags & SendFlags.Synchronous) != 0) {
+                    socket.Send(buffer, 0, buffer.Length, SocketFlags.None);
+                    return;
+                }
+                
+                lock (sendLock) {
+                    if (sendInProgress) {
+                        sendQueue.Enqueue(buffer);
+                    } else {
+                        TrySendAsync(buffer);
+                    }
+                }
+            } catch (SocketException) {
+                Disconnect();
+            } catch (ObjectDisposedException) {
+                // Socket was already closed by another thread
+            }
+        }
+        
+        void TrySendAsync(byte[] buffer) {
+            // BlockCopy has some overhead, not worth it for very small data
+            if (buffer.Length <= 16) {
+                for (int i = 0; i < buffer.Length; i++) {
+                    sendBuffer[i] = buffer[i];
+                }
+            } else {
+                Buffer.BlockCopy(buffer, 0, sendBuffer, 0, buffer.Length);
+            }
+
+            sendInProgress = true;
+            socket.BeginSend(sendBuffer, 0, buffer.Length, 0, sendCallback, this);
+        }
+        
+        static void SendCallback(IAsyncResult result) {
+            TcpLegacySocket s = (TcpLegacySocket)result.AsyncState;
+            try {
+                lock (s.sendLock) {
+                    s.socket.EndSend(result);
+                    s.sendInProgress = false;
+                    
+                    if (s.sendQueue.Count > 0) {
+                        s.TrySendAsync(s.sendQueue.Dequeue());
+                        if (s.Disconnected) s.sendQueue.Clear();
+                    }
+                }
+            } catch (SocketException) {
+                s.Disconnect();
+            } catch (ObjectDisposedException) {
+                // Socket was already closed by another thread
+            } catch (Exception ex) {
+                Logger.LogError(ex);
+            }
+        }
+        
+        // Close while also notifying higher level (i.e. show 'X disconnected' in chat)
+        void Disconnect() {
+            if (protocol != null) protocol.Disconnect();
+            Close();
+        }
+        
+        public override void Close() {
+            Disconnected = true;
+            pending.Remove(this);
+            
+            // swallow errors as connection is being closed anyways
+            try { socket.Shutdown(SocketShutdown.Both); } catch { }
+            try { socket.Close(); } catch { }
+            
+            lock (sendLock) { sendQueue.Clear(); }
+        }
+    }
+    #endif
 }
diff --git a/MCGalaxy/Scripting/Scripting.cs b/MCGalaxy/Scripting/Scripting.cs
index 0723eff1c..a8e4b8a88 100644
--- a/MCGalaxy/Scripting/Scripting.cs
+++ b/MCGalaxy/Scripting/Scripting.cs
@@ -44,6 +44,7 @@ namespace MCGalaxy.Scripting
 
         // only used for resolving plugin DLLs depending on other plugin DLLs
         static Assembly ResolvePluginAssembly(object sender, ResolveEventArgs args) {
+#if !NET_20
             if (args.RequestingAssembly == null)       return null;
             if (!IsPluginDLL(args.RequestingAssembly)) return null;
 
@@ -57,6 +58,7 @@ namespace MCGalaxy.Scripting
             
             Logger.Log(LogType.Warning, "Custom command/plugin [{0}] tried to load [{1}], but it could not be found",
                        args.RequestingAssembly.FullName, args.Name);
+#endif
             return null;
         }