This editor understands the format of NUnit project files and may be used to edit them. The project file format has not changed between NUnit V2 and NUnit 3+, so the program is useful in either context and project files may be shared between the two versions of NUnit.
The editor consists of a single executable, which may be downloaded and run from any convenient location.
You may download a zipped copy of the project editor from https://github.com/nunit/nunit-project-editor/releases or install it using Chocolatey https://chocolatey.org/packages/nunit-project-editor