https://github.com/RyanNielson/awesome-unity/blob/master/README.md#ui
Fungus
https://github.com/snozbot/fungus
ARToolKit
https://archive.artoolkit.org/documentation/doku.php?id=6_Unity:unity_about
CharacterController2D
https://github.com/prime31/CharacterController2D
TouchKit
https://github.com/prime31/TouchKit
TouchScript
https://github.com/TouchScript/TouchScript
Unity Technologies on BitBucket:
https://bitbucket.org/Unity-Technologies/ui
ProBuilder:
https://assetstore.unity.com/packages/tools/modeling/probuilder-basic-11919
SabreCSG
http://sabrecsg.com/
Nakama (Distributed networking)
https://github.com/heroiclabs/nakama
https://assetstore.unity.com/packages/tools/network/nakama-81338
UniRx
https://github.com/neuecc/UniRx
Unity Toolbag
https://github.com/nickgravelyn/unitytoolbag
Unity UI Extensions
https://bitbucket.org/UnityUIExtensions/unity-ui-extensions
Awesome Scripts:
https://github.com/SebLague?page=2&tab=repositories
Curve-Editor
https://github.com/SebLague/Curve-Editor
Gradient-Editor
https://github.com/SebLague/Gradient-Editor
Pathfinding-2D
https://github.com/SebLague/Pathfinding-2D
Pathfinding
https://github.com/SebLague/Pathfinding
Knight-Jump-Visualization
https://github.com/SebLague/Knight-Jump-Visualization
Procedural-Landmass-Generation
https://github.com/SebLague/Procedural-Landmass-Generation
Gamedev-Maths
https://github.com/SebLague/Gamedev-Maths
Intro-to-Gamedev
https://github.com/SebLague/Intro-to-Gamedev
Procedural-Cave-Generation
https://github.com/SebLague/Procedural-Cave-Generation
Procedural-Landmass-Textures
https://github.com/SebLague/Procedural-Landmass-Textures
Create-a-Game-Project
https://github.com/SebLague/Create-a-Game-Project
Chess
https://github.com/SebLague/Chess
https://github.com/UnityTechnologies
https://bitbucket.org/Unity-Technologies/
https://github.com/Unity-Technologies
http://wiki.unity3d.com/index.php/Programming
Scripts
http://wiki.unity3d.com/index.php/Scripts/General