Steam version of the mod. The author only submit the WON-version of it - which we all know is kinda dead nowadays.
Unzip the content into X:\...\Steam\steamapps\common\Half-Life\ folder and restart Steam to make it visible (listed) in your game library.
This also includes a customized GUI (background) to look-alike the WON version. Edited to suit a singleplayer mod.