Latest version of the library is available at: https://github.com/SDLash3D/xash3d
Orignal project: Xash3D on moddb
Xash3D Engine is a custom Gold Source engine rewritten from scratch. Xash3D is compatible with many of the Gold Source games and mods and should be able to run almost any existing singleplayer Half-Life mod without a hitch. The multiplayer part is not yet completed, multiplayer mods should work just fine, but bear in mind that some features may not work at all or work not exactly the way they do in Gold Source Engine.
Xash3D Engine requires Half-Life 1 SDK. Clone it with git:
git submodule init && git submodule update
Implying Half Life 1 SDK is cloned into hlsdk you should be able to
build Xash3D as:
cd xash3d
mkdir -p build
cd build
cmake -DHL_SDK_DIR=../hlsdk -DXASH_SDL=yes -DXASH_VGUI=yes -DCMAKE_OSX_ARCHITECTURES=i386 ../
make
After a successful build, copy the next files to some other directory where you want to run Xash3D:
cp engine/libxash.so game_launch/xash3d mainui/libxashmenu.so $HOME/Games/Xash3D
If you built it with XASH_VGUI, also copy vgui.so:
cp /opt/halflife/linux/vgui.so $HOME/Games/Xash3D
Copy valve folder from Half-Life:
cp -r $HOME/.steam/steam/SteamApps/common/Half-Life/valve $HOME/Games/Xash3D
Copy script:
cp ../xash3d.sh $HOME/Games/Xash3D
Run:
$HOME/Games/Xash3D/xash3d.sh
Download latest prebuilt SDL2 from
https://www.libsdl.org/release/SDL2-devel-2.0.3-VC.zip
Unzip and rename SDL2-2.0.3 folder to SDL2 and put it next to xash3d project folder.
..\xash3d\
..\SDL2\
Open xash.sln with Visual Studio 2013 and make a build. After building, copy contents of Debug or Release folder to directory you choose. Copy valve folder and vgui.dll from your Half Life game installation folder and SDL2.dll form \SDL2\lib\x86\ to it. Move vgui_support.dll into valve folder.
..\valve\
..\valve\vgui_support.dll
..\menu.dll
..\SDL2.dll
..\vgui.dll
..\xash.dll
..\xash.exe
Now you good to go, just run xash.exe.
The library is licensed under GPLv3 license, see COPYING for details. CMakeLists.txt files are licensed under MIT license, you will find it's text in every CMakeLists.txt header.