There are 3 repositories under holotoolkit-unity topic.
This repository is for the legacy Mixed Reality Toolkit (MRTK) v2. For the latest version of the MRTK please visit https://github.com/MixedRealityToolkit/MixedRealityToolkit-Unity
Mixed Reality Toolkit (MRTK) provides a set of components and features to accelerate cross-platform MR app development in Unity.