A Curated List of Open‑Source .NET Components and Frameworks

Distributed Cache Frameworks

Microsoft Velocity – Microsoft’s own distributed cache service framework.

Memcached – A high‑speed distributed caching system widely used to improve website response times.

Redis – A high‑performance key‑value store that addresses some limitations of Memcached.

EnyimMemcached – A .NET client for Memcached with advanced load‑balancing algorithms.

Recommended Open‑Source .NET Systems

OXITE – Microsoft ASP.NET MVC sample framework.

PetShop – Microsoft ASP.NET pet store example.

Orchard – An open‑source MVC blog platform.

SSCLI – Microsoft’s open‑source code from the .NET Framework 2.0 era.

DasBlog – An ASP.NET‑based blog system.

BlogEngine.NET – A free open‑source blog platform.

DotNetNuke – A robust ASP.NET portal framework.

Discuz.NET – A Chinese open‑source forum system.

nopCommerce / AspxCommerce – High‑quality open‑source B2C e‑commerce solutions.

JumboTCMS / DTCMS – Chinese open‑source website management systems.

Logging and Exception Handling

Log4Net.dll – Lightweight, free, open‑source .NET logging framework.

Enterprise Library Logging Application Block – Microsoft’s enterprise logging library.

Elmah – Popular ASP.NET exception logging framework.

NLog – Simple, flexible, high‑performance logging library.

About NoSQL Databases

MongoDB – Distributed document‑store database.

Membase – A newer heavyweight member of the NoSQL family.

Automatic Task Scheduling Frameworks

Quartz.NET – Open‑source job scheduling and automatic task framework.

Topshelf – Open‑source framework for creating Windows services.

Dependency Injection / IoC Containers

Unity – Microsoft Patterns & Practices IoC container with AOP support.

MEF (Managed Extensibility Framework) – Extensibility framework for building plug‑in systems.

Spring.NET – DI, AOP, data‑access abstraction, and ASP.NET integration.

Autofac – Popular, lightweight, high‑performance DI container.

PostSharp – Static AOP implementation with simple usage.

Ninject – Lightweight open‑source DI container for .NET.

Common ORM Frameworks

Entity Framework (EF) – Microsoft’s ADO.NET‑based ORM.

NHibernate – Lightweight ORM for .NET.

SqlMapper.cs – General‑purpose C# data‑access class for small projects.

AutoMapper – Object‑mapping library that reduces boiler‑plate code.

SubSonic – Open‑source ORM with code generation capabilities.

FluentData – Fluent‑API‑based lightweight ORM.

Dapper – High‑performance micro‑ORM generated via Emit.

EmitMapper – High‑performance ORM that emits IL at runtime.

Format and Data‑Type Conversion

Newtonsoft.Json – Popular JSON serializer for .NET and Web API.

System.JSON.dll – Microsoft’s own JSON serialization component.

DataContractJsonSerializer / DataContractXmlSerializer – Serializers used in WCF.

JavaScriptSerializer – Microsoft’s default JSON formatter for web developers.

iTextSharp, PDFsharp, PDF.NET – Libraries for creating and processing PDF documents.

SharpZipLib.dll – Open‑source ZIP/GZIP compression library.

Math.NET – Comprehensive mathematics, calculus, and scientific computing library.

DocX – Manipulate Word documents without requiring Office.

SharpSerializer – Open‑source framework for XML, binary, JSON, and compression.

Reflection and Dynamic Languages

Clay Dynamic – Open‑source dynamic language framework resembling JavaScript.

ExposedObject – Access private members via dynamic language features.

PrivateObject – Helper class in Microsoft unit‑testing framework for invoking private members.

Cross‑Platform and Runtime Solutions

Mono.NET – Cross‑platform .NET runtime.

DotGnu Portable.NET – Similar cross‑platform runtime.

Phalanger – Compiles PHP to .NET for interoperability.

VMDotNet – .NET runtime used by China Mobile’s Feixin.

Unity3D – Cross‑platform game development framework supporting C# and JavaScript.

Cassini, IIS Express, CassiniDev – Open‑source ASP.NET hosting environments.

Katana – Microsoft’s OWIN‑based non‑IIS hosting for ASP.NET/MVC.

IKVM.NET – Java virtual machine implemented on .NET.

Web Development and Design

Jumony Core – .NET‑based HTML engine.

Microsoft.mshtml.dll, Winista.HtmlParser.dll, HtmlAgilityPack.dll – HTML parsing libraries.

JavaScript.NET, ClearScript – .NET JavaScript engines.

NCrawler – Open‑source web crawler built on HtmlAgilityPack.

AntiXSS – Microsoft’s library for preventing XSS attacks.

YUICompressor.NET, Microsoft Ajax Minifier, Google Closure Compiler – JavaScript and CSS minifiers.

NancyFx – Lightweight open‑source .NET web framework.

AspNetPager – Popular ASP.NET paging control.

NOPI.dll – Excel export plugin based on OpenXml.

Enterprise Library – Microsoft’s best‑practice components for enterprise applications.

PowerCollections – Advanced collection library.

Mobile Internet and Cloud Computing

PushSharp – .NET library for sending push notifications to various mobile platforms.

Mono for Android – Develop Android apps with .NET languages.

MonoTouch – Develop iOS apps with .NET languages.

PhoneGap, AppCan – Cross‑platform HTML5‑based mobile development platforms.

Cordova – Open‑source core engine behind PhoneGap.

Network Communication and Protocols

SuperSocket – Lightweight, extensible .NET socket framework.

SuperWebSocket – .NET implementation of HTML5 WebSocket.

XProxy – Plugin‑based proxy framework with NAT, encryption, and routing features.

Graphics and Image Processing Frameworks

Paint.NET – Small, flexible open‑source graphics editor for .NET.

ImageMagick.NET – C# wrapper for the ImageMagick image‑processing library.

Skimpt – Open‑source screen‑capture tool.

ImageGlue.NET – Commercial image‑processing component.

Sprite and Image Optimization Framework – Microsoft CSS sprite generator.

Desktop Application Frameworks

DevExpress – Global UI control library for desktop applications.

Prism – Microsoft’s MVVM framework for WPF and Silverlight.

WPFToolkit, Fluent Ribbon Control Suite – Libraries for Office‑style Ribbon UI.

Testing and Performance Evaluation

Faker.Net – Framework for generating large amounts of test data.

NUnit – Lightweight unit‑testing framework.

Moq – Popular mocking framework supporting LINQ.

xUnit – Improved successor to NUnit.

MiniProfiler, Glimpse – MVC‑based performance monitoring tools.

Transaction and Distributed Transaction Support

KtmIntegration – Open‑source class providing NTFS‑based transaction support.

NET Transactional File Manager – Adds transactional semantics to file‑system operations.

Full‑Text Search and Search Engines

Lucene.NET – High‑performance full‑text indexing library.

Lucene.Net.Analysis.PanGu – Chinese segmentation extension for Lucene.NET.

Data Validation Components

FluentValidation for .NET – Validation library using fluent LINQ‑style expressions.

Microsoft.Practices.EnterpriseLibrary.Validation.dll – Validation block from Microsoft Enterprise Library.

CuttingEdge.Conditions – Contract‑programming component with fluent API.

DotNetOpenAuth – Enables OpenID, OAuth, InfoCard authentication.

Open‑Source Charting Controls

Visifire – WPF chart control with 3D rendering.

SparrowToolkit – WPF chart suite supporting dynamic curves and oscilloscopes.

DynamicDataDisplay – Microsoft’s open‑source WPF dynamic chart library.

Message Queue Extensions

Kafka – Distributed, publish/subscribe messaging system with O(1) persistence, high throughput, partitioned consumption, and both offline and real‑time processing capabilities.

RabbitMQ – Erlang‑based open‑source message broker supporting AMQP, XMPP, SMTP, STOMP, with robust routing, load‑balancing, and persistence.

Redis – Key‑value NoSQL store that also provides lightweight queue functionality; benchmarks show superior enqueue/dequeue performance for small messages compared to RabbitMQ.

ZeroMQ – Ultra‑fast, broker‑less messaging library offering non‑persistent queues; requires application‑level composition of protocols.

ActiveMQ – Apache project offering both broker and peer‑to‑peer messaging capabilities.

Kafka/Jafka – High‑performance, distributed publish/subscribe system with O(1) persistence, 10⁵ msgs/s throughput, and seamless integration with Hadoop for parallel data loading.