Most useful free .NET libraries?

Question

I have used a lot of free .NET libraries, some from Microsoft itself! Which ones have you found the most useful?

Package managers for external libraries

• NuGet (formerly known as NuPack) - Microsoft (developer-focused package management system for the .NET platform intent on simplifying the process of incorporating third party libraries into a .NET application during development)

Dependency Injection/Inversion of Control

• Unity Framework - Microsoft
• StructureMap - Jeremy Miller
• Castle Windsor
• NInject
• Spring Framework
• Autofac
• Simple Service Locator
• Managed Extensibility Framework

Logging

• Logging Application Block - Microsoft
• Log4Net - Apache
• Error Logging Modules and Handlers(ELMAH)
• NLog
• CuttingEdge.Logging

Validation

• Validation Application Block - Microsoft
• xVal

Compression

• SharpZipLib
• DotNetZip
• YUI Compressor (CSS and JS minification)
• AjaxMinifier (in other downloads) (CSS and JS minification. Also includes MSBuild task)
• SevenZipSharp to pack, unpack a lot of different packages (including RAR, 7ZIP, etc).
• ZipStorer A Pure C# Class to Store Files in Zip

Ajax

• Ajax Control Toolkit - Microsoft
• AJAXNet Pro

Data Mapper

• XmlDataMapper
• AutoMapper

ORM

• NHibernate
• Castle ActiveRecord
• Subsonic
• XmlDataMapper

Charting/Graphics

• Microsoft Chart Controls for ASP.NET 3.5 SP1
• Microsoft Chart Controls for Winforms
• ZedGraph Charting
• NPlot - Charting for ASP.NET and WinForms

PDF Creators/Generators

• PDFsharp
• iTextSharp

Unit Testing/Mocking

• NUnit
• Rhino Mocks
• Moq
• TypeMock.Net
• xUnit.net
• Gallio/MbUnit
• Machine.Specifications

Automated Web Testing

• Selenium
• Watin

URL Rewriting

• url rewriter
• UrlRewriting.Net
• Url Rewriter and Reverse Proxy - Managed Fusion

Controls

• Krypton - Free winform controls
• Source Grid - A Grid control

MS Word/Excel Documents Manipulation

• DocX to create, read, manipulate formatted word documents. Easy syntax, working nicely, actively developed. No Microsoft Office necessary.
• Excel XML Writer allows creation of .XLS (Excel) files. No Microsoft Office necessary. Been a while since it has been updated. It also provides code generator to create code from already created XLS file (saved as xml). Haven't tested this but looks very promising. Too bad author is long time gone.
• Excel Reader allows creation/reading of .XLS (Excel) files. No Microsoft Office necessary. Been a while since it has been updated.
• Excel Package allows creation/reading of .XLSX (Excel 2007) files. No Microsoft Office necessary. Author is gone so it's out of date.
• EPPlus is based on Excel Package and allows creation/reading of .XLSX (Excel 2007). It is actually the most advanced even comparing to NPOI.
• NPOI is the .NET version of POI Java project at http://poi.apache.org/. POI is an open source project which can help you read/write xls, doc, ppt files.

Social Media

• LinqToTwitter - Linq-based wrapper for all Twitter API functionality in C#

Unclassified

• CSLA Framework - Business Objects Framework
• AForge.net - AI, computer vision, genetic algorithms, machine learning
• Enterprise Library 5.0 - Logging, Exception Management, Caching, Cryptography, Data Access, Validation, Security, Policy Injection
• File helpers library
• C5 Collections - Collections for .NET
• Quartz.NET - Enterprise Job Scheduler for .NET Platform
• MiscUtil - Utilities by Jon Skeet
• Lucene.net - Text indexing and searching
• Json.NET - Linq over JSON
• Flee - expression evaluator
• PostSharp - AOP
• IKVM - brings the extensive world of Java libraries to .NET.
• C# Webserver - Embeddable webserver
• Long Path - Microsoft

[EDIT]
Please provide links to these free libraries as well. Once we have a huge list of this, it can be arranged in categories! Please do not mention .NET Applications/EXEs here.

Answer 1

nHibernate sharp zLib

Answer 2

1. Ajax Control Toolkit
2. Silverlight Toolkit
3. nUnit
4. Rhino Mocks (Unit Test against Fake Resources)
5. Moq (Unit Test against Fake Resources Alternative)
6. Flickr.Net
7. Live Services SDK
   • The following APIs are available to Live Services developers.
     1. Live Framework SDK
     2. Live Services User Data APIs
     3. Microsoft Virtual Earth SDKs
     4. Live Search API
     5. Windows Live Messenger SDKs
     6. Windows Live ID SDK
     7. Microsoft Advertising APIs
     8. Silverlight Streaming SDK
     9. Windows Live Admin Center SDK
     10. Windows Live Tools for Visual Studio Controls
     11. Windows Live Spaces SDK
     12. Windows Live Client Extensibility APIs
     13. Contacts API
     14. FeedSync (Core of LiveMesh Technology)
8. Facebook Developer Toolkit
9. Castle Windsor (DI)
10. Open XML SDK 2.0 (Create/Edit Word/Excel/PowerPoint 2007 Formats)
11. CSLA Framework (Business Objects Framework)
12. TypeMock.Net (Another Mocking framework)
13. Silverlight.FX (Additional Silverlight Controls)
14. ScriptSharp (A Javascript Framework)

Answer 3

• Unity Framework for DI
• Log4net or Elmah (for apps with a web frontend) for error logging
• NHibernate if not using Linq to Entities

Answer 4

1. Log4Net for Logging
2. Watin for Web Application Testing
3. Ajax.NET Pro for AJAX Framework. (Very successful alternative to Ajax Toolkit)
4. Json.NET JSON library for .NET
5. HTML Agility Pack for parsing HTML files.

Answer 5

Krypton Toolkit - Windows Forms Controls

Answer 6

NUnit

SharpZipLib

Log4Net

Answer 7

Two that have not been mentioned that I use a lot are:

Flee -- Expression Evaluator

PDFSharp -- PDF Editing

Answer 8

Microsoft Chart Controls for Microsoft .NET Framework 3.5

Answer 9

In-process database servers make my life easier.

SQLite

SQL Server Compact Edition

Answer 10

FlickrNet API Library

Answer 11

For PDF, other than PDFSharp,

iTextSharp

Answer 12

The Microsoft .NET Framework. I'd never get any work done without its libraries.

Answer 13

NLog for logging

Answer 14

• xUnit.net
• DotNetFireball Code Editor
• Moq
• WatiN. Automate browser-based tests during web application development.
• NHibernate
• DotNetZip
• NAnt

Answer 15

Google Data APIs Client Library

Answer 16

ELMAH

ELMAH (Error Logging Modules and Handlers) is an application-wide error logging facility that is completely pluggable. It can be dynamically added to a running ASP.NET web application, or even all ASP.NET web applications on a machine, without any need for re-compilation or re-deployment.

Update: To work with Asp.Net MVC

Answer 17

Microsoft Chart Controls for WinForms

A free high quality charting library for .NET supported by Microsoft.

Answer 18

Dependency Injection: Ninject

Web MVC framework: ASP.NET MVC (1.0 released yesterday!)

Client MVP-ish (or is that MVVM?) framework: patterns & practices Composite Application Guidance for WPF and Silverlight, aka Prism (v2 released Feb 2009)

Answer 19

Subsonic. An open source object-relational mapper.

Answer 20

Bloatware ( don't have the link )

Seriously, if you stack up log4net, NHibernate, Prism, Unity and few of them together you really get something slower than JDK 1.6. Incredible.

And it becomes such a monster for well.. pretty much bad engineering adoption magnet.

Here comes votes..

Answer 21

AForge.net

AForge.NET is a C# framework designed for developers and researchers in the fields of Computer Vision and Artificial Intelligence - image processing, neural networks, genetic algorithms, machine learning, robotics, etc.

Answer 22

I use the Spring Framework and quite like it for dependency injection.

It can do most of every sub category you specified out of the box but does not have any Ajax support. For that I use jQuery and ASP.NET AJAX.

Answer 23

The Ventaur Web Page Security project (available here: http://www.codeproject.com/KB/web-security/WebPageSecurity%5Fv2.aspx) is incredibly useful for (ASP, admittedly) .NET.

Answer 24

I've found that SharpZipLib is slow and doesn't compress nearly as good as winzip. I've used the C# version of 7-zip's LZMA algorithm is muuuch better.

Answer 25

I have found that the C5 Collections library is the most extensive and well designed collections framework for .NET.

Answer 26

Some that haven't been mentioned:

• Gentle an ORM
• Enterprise Library for validation, caching and logging
• Json.NET for Linq over Json

Answer 27

Automated web testing: Selenium. It has support for .NET.

Answer 28

How about:

Recaptcha - captcha control

url rewriter - open source URL rewriting

UrlRewriting.Net - another URL rewriter

GoogleMaps.Subgurim.NET - Google maps server control

Answer 29

Quartz.NET - Enterprise Job Scheduler for .NET Platform

Answer 30

DotNetZip for ZIP file handling.

Answer 31

nUnit and Typemock Isolator

Answer 32

LuaInterface

If you want to embed a small, fast, easy to learn and very poverful scripting language in .NET applications, this is the way to go.

Visual Web Gui

The SDK includes the complete WinForms Toolkit, 58 WinForms Controls and integration into ASP.NET. It also includes the revolutionary Visual WebGui runtime which enables desktop application-like responsiveness and heavy-lifting abilities for data centric web applications supporting multiple presentation layers* from the same source code.

Answer 33

Well, Jon Skeet's MiscUtil, of course! (Shameless plug -> My library)

Answer 34

For me, by far and away the single most useful library is:

System.Data.SQLite

Perfect for websites on a shared hosting package with fairly "light" database needs.

Answer 35

OpenNETCF, essential if you're working with Compact Framework and makes work there much less gruesome.

Answer 36

ZedGraph for graphing.

Answer 37

IKVM brings the extensive world of Java libraries to .NET.

Answer 38

I can't see a link for mbUnit which is a powerful alternative to NUnit.

Answer 39

Fluent NHibernate offers a statically compiled mapping alternative to NHibernate's XML mappings. Castle's ActiveRecord is a great implementation of the active record mapping pattern.

Answer 40

For me:

• Fluent NHibernate
• NHibernate
• log4net
• AutoFac

Answer 41

The Free and amazing SourceGrid

Answer 42

Charting

• ZedGraph
• NPlot

Winforms Controls

• DockPanel Suite
• Sharp Develop Code Editor (part of the source)

ASP.NET Controls

• FreeTextBox
• FCKEditor

Answer 43

Gallio/MbUnit for unit testing.

Answer 44

ORM - Sooda (http://sooda.sourceforge.net/)

Sooda is object-relational mapping software for the .NET (http://msdn.microsoft.com/net) environment. It lets you automatically generate an object-oriented data access layer (DAL) for your application. Instead of writing SQL code, you can now focus on writing business rules in object-oriented .NET languages.

Sooda is an open source software distributed under the terms of the BSD license.

I strongly recomend NLog which is very easy to use and very fast.

Answer 45

HTML Agility Pack. For scraping HTML and accesing it as XML.

ZedGraph. For charting in web or Windows Forms.

Answer 46

It may push the boundaries of what's considered a "library", but as a longtime advocate of embedding scripting languages into LOB applications, I'd say IronPython.

Disclaimer: I'm also biased. :)

Answer 47

NMock2 for unit-testing/mocking. NMock2

Lucene.NET: an open-source .NET port of a popular search engine API. Lucene.NET

Answer 48

DevExpress also has a free set of controls.

Answer 49

Lucene.net -> For text indexing/searching

Answer 50

For 3D graphics OpenTK is probably the best for OpenGL.

OpenTK (OpenGL for .NET and Mono.)

SlimDx (Managed DirectX, great altenative to XNA.)

Answer 51

TA-Lib for those who love trading stocks using technical analysis.

Answer 52

Microsoft Learning Components from Microsoft's SharePoint Learning Kit (www.codeplex.com/SLK) (E-Learning/SCORM libraries).

FreeImage.Net (freeimage.sourceforge.net/download.html) (.NET wrapper for FreeImage) -- I use this to get 4:4:4 subsampling for saving JPEGs.

(Can't post proper links yet.) :)

Answer 53

Please correct me if I go wrong with Microsoft.ReportViewer.

Answer 54

DevExpress has 60 free controls (both ASP.NET and WinForms)... definitely check them out...

DevExpress 60 Free Controls

Thanks :)

Answer 55

More of an XNA specific one but Farseer Physics is a great XNA 2D physics library.

Answer 56

Postsharp for aspect-oriented programming (AOP) or policy injection.

Answer 57

HTML Parsing : Html Agility Pack

Answer 58

These are the ones of those listed that I've found useful:

• DI/Ioc: Unity
• Logging: Log4Net
• Testing: NUnit, Moq
• Unclassified: Json.NET (I've played around with this a little, but haven't used it extensively.)

(We use another O/RM, but it's no longer maintained.)

This is not to say that I've fully evaluated all of the alternatives!

Other libraries of note:

HtmlAgilityPack (easy parsing of HTML)

Wow, this is hard if you leave out the EXEs and add-ins! :)

Answer 59

Sharp SVN for Subversion operations is very good.

Answer 60

More ORMS

• Linq To Entities
• db4o (object database more than ORM)
• SOODA
• NPersist
• ODX
• Coolstorage
• Lightspeed (free for less than 8 classes)

Answer 61

Spell Checker NHunspell (.NET Wrapper of the OpenOffice spell checker Hunspell).

Answer 62

Math.NET Iridium

From their homepage:

Iridium is the numerical foundation of Math.NET, aiming to provide commonly used mathematical elements for scientific numerical computations. It offers the infrastructure for basic numerics, linear algebra, random generators and distributions, integral transformations, etc.

What I've used it for is PCA (Principal Component Analysis) (eigenvalue decomposition) which worked like a charm. License: LGPL. Self-contained (no extra dependencies).

Link: http://www.mathdotnet.com/Iridium.aspx

Answer 63

You've got all of my favorite libraries covered. Here is my humble attempt to share a collection of utilities I wrote over the years and reused across various projects:

My.Utilities Class Library

This collection includes helper classes for ASP.NET web forms (time localization, etc), Windows services, error reporting, and more. Please read help file for detailed description and examples.

UPDATE: I just discovered a multi-purpose utilities library by James Newton-King, which looks pretty handy.

Answer 64

I'd like to add AutoMapper to the list, as tooling. It's so useful if you are doing any kind of application development where you are mapping DTOs or Update/View Models to domain object. It is convention based, and lets you do some awesome object mapping so easily.

Answer 65

Unclassified (specifically, serialization)

• Json.NET
• protocol buffers; protobuf-net / dotnet-protobufs

Answer 66

A great free Silverlight Charting library: Visifire

Answer 67

I would also recommend the book

:Windows Developer Power Tools: Turbocharge Windows Development with More Than 140 Free and Open Source Tools (Paperback)

Not only does it list a lot of tools it also provides information on how to use them etc. in one place.

link text

Answer 68

I've found these free Winforms Controls. They seem to be quite good and there's also a documentation and samples available. The guys also have a Free WPF Components.

Answer 69

The Fast Artificial Neural Network Library (FANN) found at http://leenissen.dk/fann/ is great.

Nice list all.

Answer 70

Code generation and O/R Mapping: My Generation.

(Sorry if this has already been posted.)

Answer 71

Open Source Enterprise Service Bus Projects:

Mass Transit - http://masstransit.pbworks.com/

NServiceBus - http://www.nservicebus.com/

Answer 72

I've created a new library for making it easier to consume REST APIs in .NET: RestSharp

Answer 73

For all your syndication & social networking needs

• RSS Toolkit : Covers publication and consumption of RSS feeds, building classes for a specific feed. Good for working with one or two feeds
• Argotic Syndication Framework : Much more useful than RSS toolkit for dealing with RSS and ATOM feeds in a generic way.
• Tweetsharp : Fluent interface to the Twitter API. Very actively developed.
• Facebook Developer Toolkit : .NET API for Facebook. v3 released last week.

Answer 74

DotNetTransitions is a library that does control animation and transitions in a WinForm application. Very smooth and easy to use.

Answer 75

Spark View Engine - a really good ASP.NET MVC (and not only) open source view engine.

Answer 76

• XML-RPC.NET by Cook Computing - A great open source XML-RPC library for dealing with services like Pingbacks and MetaWeblog API.

• NVelocity by the Castle Project - Super powerful templating library.

• Janrain OpenID library

Answer 77

Quartz.NET - Enterprise Job Scheduler for the .NET Platform.

Answer 78

Zodiac.NET is a good framework for building forms, surveys and questionnaires from XML.

Answer 79

two other cool free libraries I haven't seen in the list yet:

• NPOI which enable one to create/read/write excel files without having to install MS Office on your machine
• Protobuf-net, developped by Marc Gravell, serialization library inspired by Procotol Buffer developped by Google.

And I don't remember if someone mentions Json.NET... If not, here's the link !

Answer 80

SharpPcap - .NET pcap wrapper to capture and parse network packets

Answer 81

I can't believe nobody suggested FluentValidation so far.

Answer 82

LinFu, a framework that adds mixins, inversion of control, and AOP (see also the CodeProject articles.)

Answer 83

Nini is an uncommonly powerful .NET configuration library designed to help build highly configurable applications quickly. Generally it is about INI files.

Answer 84

IBatis is also XML-based Object/Relational mapping and persistence framework as well as a data access abstraction layer.This framework is available for .Net as well as Java too.

Answer 85

NodeXL is a great open source library for computing and visualizing Network graphs. It includes an Excel template and a .NET library with a presentation library in WPF.

Answer 86

Word / Documents:

1. DocX to create, read, manipulate formatted word documents. Easy syntax, working nicely, actively developed. No Microsoft Office necessary.

Compression

1. SevenZipSharp to pack, unpack a lot of different packages.

Excel Spreadsheets

1. Excel XML Writer allows creation of .XLS (Excel) files. No Microsoft Office necessary. Been a while since it has been updated. It also provides code generator to create code from already created XLS file (saved as xml). Haven't tested this but looks very promising. Too bad author is long time gone.

2. Excel Reader allows creation/reading of .XLS (Excel) files. No Microsoft Office necessary. Been a while since it has been updated.

3. Excel Package allows creation/reading of .XLSX (Excel 2007) files. No Microsoft Office necessary. Author is gone so it's out of date.

4. EPPlus is based on Excel Package and allows creation/reading of .XLSX (Excel 2007). It is actually my favorite when it comes to Excel. It's actively developed and so far have been able to do most things i needed (which I can't say the same about 3-5 packages), but it's only limited to .XLSX (which from one side is good thing). I'm still testing it thou :-)

5. NPOI is the .NET version of POI Java project at http://poi.apache.org/. POI is an open source project which can help you read/write xls, doc, ppt files.

Answer 87

ExcelLibrary is a really light and simple library to create and read .xls file. It has little formatting options though.

Code example to export a dataset to an Excel file :

ExcelLibrary.DataSetHelper.CreateWorkbook(@"C:\report.xls", myDataset);

Answer 88

CruiseControl.Net ? - I don't think that's listed already?

Answer 89

BlogEngine.Net

Blogger APIs

Google Chart API

Answer 90

I do not think these have been mentioned

• Dot Net Open Auth - great to help you with OpenID
• Dot less css - help with the CSS of your site

Answer 91

Sprite and Image Optimization Framework for optimizing the website images

Currently still at Preview 2

It's a part of the ASP.NET MVC Framework project on codeplex, Works fine with WebForms too

Answer 92

Since you added LinqToTwitter I think it would only be fair to add the following libraries

.NET Facebook API Client

A .NET client library for the Facebook API that allows developers to create Facebook Applications in C# and VB.NET with support for ASP.NET and ASP.NET MVC.

Facebook Developer Toolkit

This toolkit is provided as a Facebook Client Library similar to Facebook’s PHP Client Library or Facebook’s javascript library. The goal is to enable .NET developers to quickly and easily leverage the various features of the Facebook Platform.

Answer 93

Another useful ORM framework: ADO.NET Entity Framework