A Diablo II 1.11b/1.13d improvement mod. Been used on realm.angrenost.org.

• Completely reworked party screen, can handle up to 64 players
• Fixed some vanilla bugs, random crashes etc
• Expanded Sounds.Txt limit to 4954, you can easily increase to more
• Reduced TCP/IP / Open BNet join time.
• Lagometer (ported from Q3 source :D)
• Reworked ESC-menu, get rid of .dc6 files. Now creating your own menu is easy as pie (ExOptions.cpp)
• Created a lot of custom controls, you can use them to create your GUI (ie new party screen)
• Supports both 1.11b & 1.13d (set version in stdafx.h (1.11b may have missing some pointers))
• ExBuffs module let see you states, auras and remaining time
• [WIP] High resolution support for GDI / GLIDE video modes.
• Packet sender / receiver (commands #send, #recv)
• Items stat range (press CTRL + hoover on an item)

You can set build flags in stdAfx.h. However flags related to D2EX_PVPGN_EXT won't work for you unless you have serverside DLL which i won't make public.
List of flags / values you can set:

• D2EX_CLOSED_BNET: make hack usable on closed bnet
• D2EX_SCRAP_HACKS: some random hacks like bugged wsg
• D2EX_MULTIRES: enables high resolution settings
  • D2EX_OPENGL: experimental, enables OpenGL render mode (ExOpenGL.cpp / ExTexture.cpp is not available in the repo, so it won't work for you)
  • D2EX_ALLOWHIGHRES: enables support for 800x600+
  • D2EX_MINIMALRES: restrict resolution to 1024x768 and 1280x1024
• D2EX_PVPGN_EXT: enables serverside stuff like kill counter, spectator mode etc. All the following subflags needs serverside changes to work.
  • D2EX_PVPGN_GIVEUP: adds Give up to ESC menu
  • D2EX_ARGOLD: enables client support for virutal gold service in trade window
  • D2EX_FORUMGOLD: enables client support to replace gold with external forum gold currency
  • D2EX_SPECTATOR: enables client support for spectator mode
    • D2EX_SPECTATOR_STATE: states.txt record set on spectators
  • D2EX_COLOR_STAT: itemStatCost.Txt record which stores item color value
  • D2EX_LOOTED_STAT: itemStatCost.Txt record which stores monster id which gave the item
  • D2EX_CUSTOM_CUBE_RECIPES: Adds "portal" keyword to CubeMain.Txt output
• D2EX_EXAIM_ENABLED: experimental -- never finished -- abandoned project of intelligent autoaim
• D2EX_PVM_BUILD: enables maphack with monsters on the map, autotele, etc.
• D2EX_MAX_SND_TXT_ROWS: maximum rows in Sound.txt
• D2EX_I_NEED_CUBE: define if you need transmute button, otherwise it will be used as auto-precast feature
• D2EX_TP_RANGE: maximum teleport range for AutoTele
• D2EX_ENABLE_PACKET_COMMANDS: enables packet commands in Release build
• D2EX_DEBUG_INFO: Show current mouse X&Y, and the selected unit id in Release build
• D2EX_PRINT_ITEMLEVEL: Print "Item Level" on an item description
• D2EX_EXTENDED_LEVELS: Extends Levels.txt limit to 255

1. Compile Release build (select configuration for your version) using Visual Studio 2012 or newer.
2. Copy everything from files directory to your Diablo II directory, D2Win.dll is a loader for D2Ex2.dll. If you use prebuilt D2Ex2.dll, then you'll need to install this: http://www.microsoft.com/en-us/download/details.aspx?id=40784
3. Warning: Files ExOpenGL.cpp and ExTexture.cpp/h are not included in this repo. You have to remove them manually from Solution Explorer to make build succeed.

• 22 vs 22 video (Early version)
  
• Party screen with kill/assist/death counter
  
• Stat range (CTRL + hover on an item)
  
• Buffs
  
• Can you guess what resolution it is?
  

Vav for motivation
MrMag-WS for testing platform
RoluS/Zurek/InteR for some great ideas
Phrozen Keep forums for great source of informations