Antechinus
A programmer's editor that supports color-coded syntax of the C# programming language. By C Point Pty Ltd.
Blue Ink
A C# application generating software program that decrease development time for database enabled web applications. [Commercial]
C# Rapid Development Kit
A series of advanced collections and more than 50 generic algorithms that are designed to complement, not replace, the basic features found in the .NET Framework. [Commercial]
C# Refactory
A refactoring, metrics and productivity add-in for Microsoft Visual Studio.NET.
Clover.NET
Clover.NET provides code coverage for .NET projects. Measures method, statement and branch coverage. reports in XML, HTML or via Visual Studio Plugin. A suite of NAnt tasks are provided. [Free for Open Source and Non-commercial projects]
C-Sharpener For VB
A Visual Studio addin that converts VB.Net projects to C# projects. [Commercial, free conversion service for open source projects]
db4o
An object database written in C# for the .NET platform. Also exist Java version.
DotGnu Portable .NET
An open-source C# compiler and libraries.
Editor Hub - C#
List of editors with C# support with reviews. Sorted by platforms and licenses.
eXtensible C#
Provides attribute-based declarative assertions, partial based code verification and obfuscation for C#. Free download.
Free Compiler Writing Tools
Provides C# source for tools written in the tradition of lex and yacc, redesigned in an object-oriented way. By Malcolm Crowe.
HKPGEN Plugins Generator
Visually design plugins for HTML-Kit and automatically generate source code in .NET C#
HTML-Kit
Highly customizable free C# editor. Includes syntax highlighting and lookup of online and offline help references.
Improve C# plugin for Eclipse
Free open-source plugin for Eclipse (itself a free and open-source development environment) with syntax highlighting, content assistant (intellisense for C# keywords), and ability to compile code from within the IDE.
Instant C#
Convert VB.NET code to C# code at the project and code snippet levels. Description, sample screenshots, and ordering information. By Tangible Software Solutions Inc.
Mentalis.org
A collection of classes written in C# and VB.NET.
MonoDevelop
A project to port SharpDevelop to Gtk#.
Nini
A software configuration library written in 100% C# for the .NET Framework. This software contains a concise API for abstracting the access of multiple configuration types: INI, .NET config files, registry, XML files, and command-line options. [Open source, MIT License]
OCL (Open CLI Library)
Intel Labs C# implementation of portions of the CLI (Common Language Infrastructure) runtime library as defined in the draft ECMA CLI specification.
OpenGL for C#
Provides C# wrapper for OpenGL & SDL along with some tools.
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