A maintained collection of useful & free unity scripts / library's / plugins and extensions.
If you want to suggest a link, then read the Contribution Guidelines first. Please report broken links, outdated assets and spelling mistakes. The links are in no particular order.
Navigation:
- GameObjects & Transforms
- Movement & Animation
- Controls & Input
- Character Controller
- AI & Pathfinding
- Physics
- Particles
- Meshes & Construction
- Materials & Shading
- 2D
- Networking
- VR
- Sound & Music
- UI
- Post-Processing & Rendering
- Mobile
- Debug
- Editor
- Serialization & Web
- Social SDKs
- API Extensions & Helper
- Design Patterns
- Other
- RecyclerKit - pooling system
- UnityOctree - octrees
- In-Game Replay System - record and replay transforms
- List View Framework - create dynamic, scrollable lists
- Reaktion - audio reaction toolkit
- DOTween - tween engine
- UnitySpritesAndBones - skeletal sprite animations
- spine-unity - import spine animations
- InputManager - a powerful input manager
- TouchScript - multitouch library
- Unity 2D Platformer Controller - 2d platformer character controller
- CharacterController2D - 2d character controller
- SuperCharacterController - 3d character controller
- A Star Pathfinding for Platformers - A* for platformers
- AStart - basic A* pathfinding
- Astar for Unity - A* pathfinding
- A* Pathfinding Project - A* pathfinding
- UnitySteer - steering, obstacle avoidance and path following behaviors
- Mario Galaxy Gravity for Unity - mario galaxy gravity
- Ocean Community Next Gen - water physics/shader
- KvantSpray - gpu accelerated particles
- NVIDIA Hair Works Integration - Nvidia hair works
- ProceduralToolkit - procedural mesh toolkit/generator
- Draw - draws primitives with lines
- VolumetricLinesUnity - volumetric lines
- giles - 3d runtime level editor
- Voxelmetric - voxel framework
- Procedural Shapes for Unity - procedural shapes
- ICO Sphere Mesh Creator - procedural ico spheres
- Vertex Painter - paint information onto vertices
- FacePaint - paint triangles of meshes
- Simplygon - mesh optimization & lod generation
- TextMesh Pro - generate text with custom styling
- Projects by RM - wet surface & skin shader
- Ocean Community Next Gen - water physics/shader
- Flow Map Shader - flow map shader working with sprites
- VertexPaint - additional vertex streams
- ShaderProject - shader collection
- Skybox Plus - a collection of skybox shaders
- Outline Shader - outline shader which accomodates screen width and camera distance
- Unity Sprite Uber Shader - 3D shading for sprites (e.g. normal mapping)
- UnitySVG - svg renderer
- UnityStbEasyFont - text mesh generator
- SpriteLightKit - 2d sprite lights
- 2D Light of Sight Unity - 2d flat geometric lightning
- Unity Sprite Uber Shader - 3D shading for sprites (e.g. normal mapping)
- Fungus - 2d interactive storytelling game framework
- PolyMesh - 2d shape editor
- Unity Tilemap - 2D tilemap editor
- UNet Authoritative Networking - authoritative networking implementation
- SteamVR - VR SDK
- The Lab Renderer - VR renderer by Valve
- VRTK - contains useful scripts for building VR games
- NewtonVR - VR physics and interactions
- Cutie Keys - VR keyboard
- usfxr - procedual audio effects
- Reaktion - audio reaction toolkit (mac only)
- DefaultMicrophone - gets the default microphone (windows only)
- Unity UI Extensions - collection of ui extensions
- Book Page Curl - page curl transition
- Open Pause Menu - read-to-use pause menu
- Lunar Mobile Console - debug console for mobiles
- InfinityScroll - infinite scrollrects
- TextMesh Pro - generate text with custom styling
- kode80SSR - screen-space reflections
- KinoObscurance - screen-space ambient obscurance
- SMAA - subpixel morphological anti-aliasing
- Temporal Reprojection Anti-Aliasing - anti-aliasing solution used in INSIDE
- kode80CloudsUnity3D - realtime volumetric clouds
- PixelRenderUnity3D - pixelized rendering
- PixelCamera2D - pixel-perfect rendering
- KinoMotion - motion blur using motion vectors
- KinoContour - edge detection
- KinoMirror - kaleidoscope effect
- KinoFringe - chromatic aberration
- KinoBinary - 1-bit monochrome effect
- KinoFeedback - retro framebuffer feedback effect
- KinoRamp - color ramp overlay
- KinoSlitscan - slit-scan effect
- KinoGlitch - glitch effect
- KinoDatamosh - datamosh
- unity vhsglitch - vhs glitch effect
- Scanline Shader - scanline effect
- KinoFog - global fog
- KinoBloom - bloom
- KinoBokeh - bokeh effect
- KinoVignette - vignette
- KinoVision - frame information visualizer
- Unity5Effects - post-processing collection
- LightShafts - light shafts
- VolumetricLights - volumetric lights
- SonarFx - wave patterns
- Cinematic Image Effects - cinematic image effects
- Post-processing Stack - multiple image effects in one pipeline
- Moments - gif recorder
- uDesktopDuplication - realtime screen capture as Texture2D
- Heat Distortion Effect - a shader which distorts the image behind, using a normal map
- Toast - android toast notifications
- FBSucks - android share image & text
- UnityShowAndroidStatusBar - android show statusbar
- Google VR SDK - google mobile vr sdk
- Unity Webview - webview overlay
- CUDLR - remote debugging and logging console
- Simplygon - mesh optimization & lod generation
- uREPL - runtime evaluation of c# expressions
- UberLogger - advanced logging API, improved editor console & ingame console
- REX Diagnostics - runtime evaluation of c# expressions
- Better Defines - platform dependent preprocessor directive manager
- Unity File Debug - enhanced logging
- MissingReferencesUnity - find missing references
- Unity Resource Checker - resource analyzer
- Compile Time Tracker - compile time tracker
- UnityStudio - unity asset export tool
- Screen Shooter - takes screenshots with multiple resolutions at once
- Script Templates for Unity - script templates
- Unity 2D Destruction - sprite destruction
- CurveTexture - bake curves into texture
- Unity3D Rainbow Folders - folder icons
- Unity Themes - editor themes
- Tree Randomizer - randomize unity trees
- Render Settings Duplicator - clones the render settings from one scene to another
- Piviot Transform Helper - adds piviot creation shortcuts to the context menu
- ScriptExecutionOrder Attribute - attribute to specify execution order
- Brainiac - behaviour tree & (behaviour-)node-based visual editor
- Node Editor - (calculation-)node editor
- BrotherhoodOfNode - (more graphical-)node editor for visual things
- VisualNoiseDesigner - visual noise designer
- SimpleGeo - simple geometry painter
- Curves and Splines - curve & spline editor
- Unity 2D Joint Editors - 2d joint editors
- PolyMesh - 2d shape editor
- VertexPaint - vertex data painter
- SabreCSG - a set of level design tools for building complex levels
- Constants Generator Kit - generates static classes for layers, scenes, tags and resources
- Unity Tilemap - 2D tilemap editor
- Reorderable Lists - reorderable list field
- Ordered Dictionary - ordered dictionary field
- ClassTypeReference - class type reference field
- Unity3D ExtendedEvent - extended event selector
- Property Drawer Collection - collection of property drawers
- Node Inspector - node based inspector
- ColorBands - color bands
- QuickEvent - persistent event handlers with static or dynamic values
- Reorder Components - reorder components on your GameObjects
- Unity Excel Importer Maker - excel
- Unity Psd Importer - advanced psd import
- Full Serializer - custom serializer
- Json.Net - Newtonsoft Json.NET
- SQLite4Unity3d - sql lite
- UnityHTTP - http library
- Google Analytics Plugin - Google Analytics
- Google Play Games Plugin - Google Play plugin
- Facebook SDK - Facebook sdk
- Reign Unity Plugin - unified mobile api
- GetSocial SDK - community api
- SOOMLA Framework - store api
- Steamworks.NET - c# wrapper for valve's Steamworks API
- Facepunch.Steamworks - Steamworks C# API (not all features implemented, but better API)
- Camera Extension - a better way of manipulating the culling mask
- Download Manager - simple file downloads
- UnityMainThreadDispatcher - main thread dispatcher
- UnityBitmapDrawing - texture2d drawing extensions
- Unity3D ComponentAttribute - auto component referencing
- Unity3D ExecutionOrderAttribute - execution order attribute
- LINQ to GameObject for Unity - gameobject linq querys
- Chained Works - coroutine chained procedures
- TeaTime - timer queue for coroutines
- Smart Tags and Layers - generates static values for your tags and layers
- Unity Singleton MonoBehaviour - powerful singleton
- Signals - simple event/signal system
- Unity3d Finite State Machine - simple finite stata machine
- stateless - more complex state machines
- Design Patterns in Unity Example - collection of design patterns
- Entitas CSharp - entity component system framework
- strangeioc - inversion of control framework
- Zenject - depedency injection framework
- UniRx - unity reactive extensions implementation
- Unity Right Click - windows context menu extension: 'open with unity'
- No Hot-Reload - prevent unity hot-reloads
- Unity Decompiled - unity 5.3 decompiled
- Unity C# 5.0 and 6.0 Integration - c# 5 & 6 integration for unity
- FLUnity - flash to unity
- Projeny - project management
- CUDLR - remote debugging and logging console
- WebGL - Simple Loading Fix - custom loading bar for the webgl loader
- UtilityKit - SerializationUtil, SpriteAnimator, SpriteAnimator, MathHeloers, AutoSnap, ...
- Remove Boo.Lang and UnityScript Hints - Project Generation Hook to remove references to Boo.Lang and UnityScript assemblies
- Asset Store Batch Mode - API for uploading Unity Asset Store packages
- Unity Size Explorer - analyzes the disk space usage of your build
I collected most links over multiple years, but I also got some from: