Nez aims to be a lightweight 2D framework that sits on top of MonoGame/FNA. It provides a solid base for you to build a 2D game on. Some of the many features it includes are:

Scene/Entity/Component system with Component render layer tracking and optional entity systems (an implementation that operates on a group of entities that share a specific set of components)
SpatialHash for super fast broadphase physics lookups. You won't ever see it since it works behind the scenes but you'll love it nonetheless since it makes finding everything in your proximity crazy fast via raycasts or overlap checks.
AABB, circle and polygon collision/trigger detection
Farseer Physics (based on Box2D) integration for when you need a full physics simulation
efficient coroutines for breaking up large tasks across multiple frames or animation timing (Core.startCoroutine)
in-game debug console extendable by adding an attribute to any static method. Just press the tilde key like in the old days with Quake. Out of the box, it includes a visual physics debugging system, asset tracker, basic profiler and more. Just type 'help' to see all the commands or type 'help COMMAND' to see specific hints.
in-game Component inspector. Open the debug console and use the command inspect ENTITY_NAME to display and edit fields/properties and call methods with a button click.
extensible rendering system. Add/remove renderers and post processors as needed. Renderables are sorted by render layer first then layer depth for maximum flexibility out of the box.
pathfinding support via Astar and Breadth First Search
deferred lighting engine with normal map support and both runtime and offline normal map generation
tween system. Tween any int/float/Vector/quaternion/color/rectangle field or property.
sprites with sprite animations, scrolling sprites, repeating sprites and sprite trails
flexible line renderer with configurable end caps including super smooth rounded edges or lightning bolt-like sharp edges
kick-ass particle system with added support for importing Particle Designer files
optimized event emitter for core events that you can also add to any class of your own
scheduler for delayed and repeating tasks (Core.schedule method)
per-scene content managers. Load your scene-specific content then forget about it. Nez will unload it for you when you change scenes.
customizable Scene transition system with several built in transitions
Verlet physics bodies for super fun, constraint-to-particle squishy physics
tons more stuff

Nez Systems

There are various systems documented separately on the Nez website docs. You can also access the markdown files directly below. Note that sometimes the Nez website docs lag behind the markdown files linked below.

Setup

Quick version:

clone or download the Nez repository
add the Nez-PCL/Nez.csproj project to your solution and add a reference to it in your main project
make your main Game class (Game1.cs in a default project) subclass Nez.Core

(optional) Pipeline Tool setup for access to the Nez Pipeline importers

add the Nez.PipelineImporter/Nez.PipelineImporter.csproj project to your solution
open the Nez.PipelineImporter references dialog and add a reference to the Nez project
build the Nez.PipelineImporter project to generate the DLLs
open the Pipeline Tool by double-clicking your Content.mgcb file and add references to PipelineImporter.dll, Ionic.ZLib.dll, Newtonsoft.Json.dll and Nez.dll.

All Nez shaders are compiled for OpenGL so be sure to use the DesktopGL template, not DirectX! Nez only supports OpenGL out of the box to keep things compatible across Android/iOS/Mac/Linux/Windows.

If you intend to use any of the built in Effects or PostProcessors you should also copy or link the DefaultContent/effects folder into your projects Content/nez/effects folder. Be sure to set the Build Action to Content and enable the "Copy to output directory" property so they get copied into your compiled game.

If you are developing a mobile application you will need to enable touch input by calling Input.touch.enableTouchSupport().

Pipeline Importers

Nez comes stock with a decent bunch of Pipeline tool importers including:

Texture Atlas Generator: give it a directory or a list of files and it will combine them all into a single atlas and provide easy access to the source images at runtime. Supports nine patch sprites as well in the Android style (single pixel border with black lines representing the patches). See also this generator. The Texture Atlas Generator also includes a per-folder sprite animation generation. The atlas generator uses an XML file as input with an Asset Type of System.String[]. The string array should specify the folder or folders where the source images are located.
Tiled: import Tiled maps. Covers tile, image and object layers and rendering with full culling support built-in along with optimized collider generation.
Bitmap Fonts: imports BMFont files (from programs like Glyph Designer, Littera, etc). Outputs a single xnb file and includes SpriteBatch extension methods to display text the directly match the SpriteFont methods.
Particle Designer Importer: imports Particle Designer particle systems for use with the Nez particle system
LibGdxAtlases: imports libGDX texture atlases including nine patch support
Texture Packer: imports a TexturePacker atlas and JSON file
Overlap2D: imports Overlap2D projects. Imports most of the data but currently only offers renderers for the basics (no fancy stuff like Spriter animations, lights, etc).
UISkin Importer: imports uiskin files (JSON format) that are converted to UISkins. See the UI page for an example and details of the JSON format.
Normal Map Generator: generates normal maps from standard textures
XMLTemplateMaker: this isn't so much an importer as a helper to make your own importer. Pass it a class and it spits out an XML template that you can use for your own custom XML-to-object importers.

Samples Repository

You can find the samples repo here. It contains a variety of sample scenes that demonstrate the basics of getting stuff done with Nez. The wiki also contains a few short examples. This YouTube playlist also has a few relevant videos.

Using Nez with FNA

See the Nez.FNA repo for details.

Acknowledgements/Attributions

Bits and pieces of Nez were cherry-picked from various places around the internet. If you see something in Nez that looks familiar open an issue with the details so that we can properly attribute the code.

I want to extend a special thanks to three people and their repos listed below. The Monocle Engine and MonoGame.Extended allowed me to get up and running with MonoGame nearly instantly when I was first evaluating if it would be a good alternative to use for making games. libGDX scene2D UI was ported over to Nez to get a jump start on a UI as well. Nez uses a bunch of concepts and code from all three of these repos.

Matt Thorson's fantastic Monocle Engine

Dylan Wilson's excellent MonoGame.Extended and his initial work on converted Farseer Physics Engine to a Portable Class Library. Farseer is Microsoft Permissive v1.1 licensed.

Nathan Sweet's libGDX Scene2D UI libGDX. Nez UI is based on libGDX Scene2D which is Apache licensed.

garthwales/Nez