Outline Generator is a Blender addon from JSoftWorks that creates and manages an outline effect on selected objects. The effect is obtained through a combination of modifiers and shaders, and it can be applied across multiple objects in a scene.
In Blender, modifiers and shaders are normally applied per object. While there are ways to act on several objects at once, doing so isn't always easy or intuitive. This addon focuses on that gap, handling the outline setup across multiple objects to save artists time and effort. The outline effect itself is used across different styles and application fields.
The listed render engine is Eevee, and the addon is compatible with Blender versions 2.93 through 5.1. It's released under the GPL license and ships with documentation. A demo video is available, and it holds a 5-star rating from two reviews on Superhive.