Changed IGuiHandler's signature to be compatible with both sides. Took out ModLoaderMp reference in README.

forge/forge_client/src/net/minecraft/src/forge/IGuiHandler.java

@@ -1,21 +0,0 @@
-package net.minecraft.src.forge;
-
-import net.minecraft.src.EntityPlayerSP;
-import net.minecraft.src.GuiScreen;
-import net.minecraft.src.World;
-
-public interface IGuiHandler
-{
-    /**
-     * Returns a GuiScreen to be displayed to the user. This is client side
-     *
-     * @param ID The Gui ID Number
-     * @param player The player viewing the Gui
-     * @param world The current world
-     * @param X X Position
-     * @param Y Y Position
-     * @param Z Z Position
-     * @return A GuiScreen to be displayed to the user, null if none.
-     */
-    public GuiScreen getGuiScreen(int ID, EntityPlayerSP player, World world, int X, int Y, int Z);
-}

forge/forge_common/net/minecraft/src/forge/IGuiHandler.java

@@ -0,0 +1,22 @@
+package net.minecraft.src.forge;
+
+import net.minecraft.src.EntityPlayer;
+import net.minecraft.src.World;
+
+public interface IGuiHandler
+{
+    /**
+     * Returns a Container to be displayed to the user. 
+     * On the client side, this needs to return a instance of GuiScreen
+     * On the server side, this needs to return a instance of Container
+     *
+     * @param ID The Gui ID Number
+     * @param player The player viewing the Gui
+     * @param world The current world
+     * @param x X Position
+     * @param y Y Position
+     * @param z Z Position
+     * @return A GuiScreen/Container to be displayed to the user, null if none.
+     */
+    public Object getGuiElement(int ID, EntityPlayer player, World world, int x, int y, int z);
+}

forge/forge_server/src/net/minecraft/src/forge/IGuiHandler.java

@@ -1,21 +0,0 @@
-package net.minecraft.src.forge;
-
-import net.minecraft.src.Container;
-import net.minecraft.src.EntityPlayerMP;
-import net.minecraft.src.World;
-
-public interface IGuiHandler
-{
-    /**
-     * Returns a Container to be displayed to the user. This is server side
-     *
-     * @param ID The Gui ID Number
-     * @param player The player viewing the Gui
-     * @param world The current world
-     * @param X X Position
-     * @param Y Y Position
-     * @param Z Z Position
-     * @return A GuiScreen to be displayed to the user, null if none.
-     */
-    public Container getGuiContainer(int ID, EntityPlayerMP player, World world, int X, int Y, int Z);
-}

forge/install/README.txt

@@ -4,8 +4,8 @@ Extract the download archive directly into your MCP-directiory.
 It should create a folder "forge" within that directory, containing all 
 extracted files.
 
-You should use freshly downloaded jars, solely including ModLoader & 
+You should use freshly downloaded jars, solely including ModLoader in the 
-ModLoaderMP. Anything else can eventually cause conflicts.
+client jar. Anything else can eventually cause conflicts.
 
 You also need to install the FernFlower decompiler, you can download it at 
 http://goo.gl/PnJHp. Extract fernflower.jar into your MCP's runtime/bin folder.

forge/patches/minecraft/net/minecraft/src/EntityPlayer.java.patch

@@ -153,7 +153,7 @@
 +            IGuiHandler handler = MinecraftForge.getGuiHandler(mod);
 +            if (handler != null)
 +            {
-+                GuiScreen screen = handler.getGuiScreen(ID, (EntityPlayerSP)this, world, x, y, z);
++                GuiScreen screen = (GuiScreen)handler.getGuiElement(ID, this, world, x, y, z);
 +                if (screen != null)
 +                {
 +                    ModLoader.getMinecraftInstance().displayGuiScreen(screen);

forge/patches/minecraft_server/net/minecraft/src/EntityPlayer.java.patch

@@ -168,7 +168,7 @@
 +        IGuiHandler handler = MinecraftForge.getGuiHandler(mod);
 +        if (handler != null)
 +        {
-+            Container container = handler.getGuiContainer(ID, player, world, x, y, z);
++            Container container = (Container)handler.getGuiElement(ID, player, world, x, y, z);
 +            if (container != null)
 +            {
 +                player.realGetNextWidowId();