Costura
A Fody add-in for .NET that embeds a project's dependency assemblies as resources so an application or library ships as a single file.
Costura is an add-in for Fody, the .NET IL-weaving tool. It takes assemblies and PDBs marked Copy Local and embeds them as resources inside the target assembly, then injects a module initializer that loads them from those resources at runtime if the normal assembly load fails.
It is installed as a NuGet package alongside Fody and configured through FodyWeavers.xml, with no additional code required in the project. It supports both library and executable projects on Windows.
The project is in maintenance mode: .NET Core 3 added single-file executables and assembly linking, which cover most of what Costura provided, so new use cases beyond C# library and executable linking on Windows are no longer actively supported.