Source+ is a custom tool for developing mods in Valve's Source Engine. Source+ takes the iconic Engine and converts it into a Game Engine more in-line with the Engines of today by giving it a custom editor & a multitude of additional tools to help make the development workflow much easier.
- Microsoft Visual Studio 2026 with the following workflows & components:
.NET desktop developmentworkflow.NET 10.0 RuntimeNuGet package managerNuGet targets and build tasks
To build the project, go to the src folder in your operating system's terminal and use the dotnet build command.
In Visual Studio, go to the top menu & open the Build menu. There, you can pick on whether to build the solution or just the current project.
Alternatively, you can use the Ctrl + Shift + B and Ctrl + B shortcuts to build the solution and current project respectively.
To debug using Visual Studio, go an click on the green arrow with the text SourcePlus next to it or press F5.
The Source+ Editor is licensed under the MIT License, which you can read here.
The Source SDK and, by extension, the projects that you create are, by default, licensed under Valve's SOURCE 1 SDK License, which can be read here.