First step, open a new terminal and enter the commands below:

1. (Linux) sudo apt install git - This will install git if not already installed (Ubuntu/Debian-based Linux variants). If you're using a non-Debian flavour of Linux, use the default package manager that comes with it to install git instead.
2. (macOS) xcode-select --install - This will install git if not already installed, along with required make and gcc tools
3. git clone https://github.com/UOX3DevTeam/UOX3.git - This will clone the stable master branch of the UOX3 git repository into a subdirectory of the current directory you're in, named UOX3. The latest verified compatible version of SpiderMonkey (v1.7.0) is also included, as well as a minimal set of files required to compile zlib-1.2.11.

1. Download and install the macOS version of GitHub Desktop.
2. Run GitHub Desktop and click File->Clone Repository from the menu.
3. Click the URL tab, enter https://github.com/UOX3DevTeam/UOX3.git, then provide a local path for where you want the UOX3 git repository cloned on your drive.
4. Hit the Clone button!

You'll need a couple tools before you can compile UOX3 on Linux, like GNU Make (v4.2.1 or higher recommended) and gcc (v9.x or higher recommended). Install these through your favourite package manager or through your flavour of Linux' variant of the following terminal command (example specific to Debian/Ubuntu Linux flavours):

1. (Linux only) sudo apt install build-essential

Once these are in place, navigate to the UOX3 project folder in your terminal and execute the following command from the project's root directory:

./automake.sh - First compiles the SpiderMonkey JS library bundled with UOX3, then compiles the included zlib library, and finally compiles the actual UOX3 build, before copying the compiled binary to the root UOX3 project directory.

If your version of gcc is below 9.x, you'll need to add -lstdc++fs in Makefile to include the experimental filesystem library from c++17.

Change the following line (~34) from

`$(CXX) $(CXXFLAGS) -o $(TARGET) $^ $(LDFLAGS)`

to

`$(CXX) $(CXXFLAGS) -o $(TARGET) $^ $(LDFLAGS) -lstdc++fs`

If you don't wish to rely on the automake.sh script, but want control over the process yourself, follow these steps (same as what automake.sh does):

• cd spidermonkey
• make -f Makefile.ref DEFINES=-DHAVE_VA_LIST_AS_ARRAY CC=gcc

Linux

• ar -r libjs32.a Linux_All_DBG.OBJ/*.o
• cp Linux_All_DBG.OBJ/jsautocfg.h ./

macOS

• ar rcs libjs32.a Darwin_DBG.OBJ/*.o
• cp Darwin_DBG.OBJ/jsautocfg.h ./

Next up, compile a static library of the included zlib package:

• cd ../zlib
• make distclean
• ./configure
• make

At this point, now cd to the root UOX3 project directory and build UOX3:

• cd ../source
• make

This is an example of how to copy all required files to a directory called UOX3 in your user account's home directory

1. navigate to root UOX3 project directory
2. mkdir ~/UOX3
3. cp uox3 ~/UOX3
4. cp -r data/* ~/UOX3
5. cd ~/UOX3

This option will let you use Visual Studio solution/project files to compile both UOX3 and SpiderMonkey with Visual Studio's default VC++ compiler. Note that you can download the Free Community edition of Visual Studio if you don't have it already. This approach also embeds SpiderMonkey directly inside UOX3 for a slightly larger (~1-2MB) executable, instead of requiring a separate DLL file, and comes with options for compiling either 32-bit or 64-bit (default) versions of UOX3.

Note: You'll need to install "Desktop development with C++" via the Visual Studio Installer if you don't have it already, along with the option for this titled MSVC v141 - VS 2017 C++ x64/x86 build tools (v14.16)

SpiderMonkey

1. Navigate to the UOX3\spidermonkey folder and open SpiderMonkey.sln in Visual Studio.
2. Make sure you have js32 selected in the Solution Explorer, then select Release and either x64 (64-bit) or Win32 (32-bit) in the Solution Configuration/Platform dropdown menus
3. Click Build > Build js32 from the menu.
4. Visual Studio will compile SpiderMonkey and create spidermonkey\Release\x64 (64-bit) or spidermonkey\Release\x86 (32-bit) folders with the compiled js32.lib library file contained within. No further actions are necessary here, so you can close the SpiderMonkey VS Solution.

zlib

1. Navigate to the UOX3\zlib folder and open zlib.sln in Visual Studio.
2. Select Release and either x64 (64-bit) or Win32 (32-bit) in the Solution Configuration/Platform dropdown menus
3. Click Build > Build zlib-static from the menu.
4. Visual Studio will compile zlib and create zlib\x64\Release (64-bit) or zlib\x86\Release (32-bit) folders with the compiled zlib-static.lib library file contained within. No further actions are necessary here, so you can close the zlib VS Solution.

UOX3

1. Open UOX3_Official.sln from the UOX3\source folder.
2. Make sure you have UOX3_Official selected in the Solution Explorer, then select either Release or Debug, and either x64 (64-bit) or Win32 (32-bit) in the Solution Configuration/Platform dropdown menus, or via Build -> Configuration Manager.
3. Select Build -> Build UOX3_Official to start compiling UOX3. When done, you'll find UOX3.exe either in UOX3\source\Release\x64 (or \x86) or in UOX3\source\Debug\x64 (or \86), depending on your choices in the previous step.

This option requires installing the Visual Studio toolset named Linux development with C++ and the component called Visual C++ tools for CMake and Linux. Use the Visual Studio Installer to modify your install of Visual Studio if you don't already have these installed! This approach compiles SpiderMonkey to a separate DLL (js32.dll) file that needs to live inside the same folder as the main UOX3 executable, and currently only supports compiling a 32-bit version of UOX3.

1. Start Visual Studio and use File > Open > CMake and select CMakeLists.txt in the root project folder (Example: D:\UOX3). Don't open the similarly named file in the source folder directly.
2. After Visual Studio is done loading the project and has generated some necessary files, select CMake > Change CMake Settings > UOX3 from the toolbar menu, and select either x86-Debug or x86-Release depending on what kind of build you want to make - or do this using the Solution Configuration select menu.
3. When Visual Studio is done switching to the new configuration, select CMake > Build All from the toolbar menu to start compiling UOX3.
4. When done, you'll find uox3.exe and js32.dll in a subfolder named out of the root project folder, more specifically /UOX3/out/build/x86-Debug or x86-Release, based on the selected configuration.
5. Note that the js32.dll file must be copied to the same folder as UOX3.exe.