Ursa is an enterprise level UI library for building cross-platform applications with Avalonia UI.

Dev Proxy is an API simulator that helps you effortlessly test your app beyond the happy path.

Bootstrap Blazor is an enterprise-level UI component library based on Bootstrap and Blazor

A MessagePack serialization library for .NET

The .NET Aspire Community Toolkit is a collection of integrations and extensions for developing with .NET Aspire, extending the core functionality provided by .NET Aspire.

The .NET MAUI Community Toolkit is a collection of reusable elements for application development with .NET MAUI, including animations, behaviors, converters, effects, and helpers. It simplifies and demonstrates common developer tasks when building iOS, Android, macOS and WinUI applications using .NET MAUI.

.NET Community Toolkit is a collection of helpers and APIs that work for all .NET developers and are agnostic of any specific UI platform. The toolkit is maintained and published by Microsoft, and part of the .NET Foundation.

MiniExcel is simple and efficient to avoid OOM's .NET processing Excel tool.

This project aims to ensure high-quality support for JSON-based technologies in .Net. Supports JSON Schema, JSON Path, JSON Patch, and more.

A complete and maintained cross-language implementation of the Uri Template specification RFC 6570 Level 4

The Community Datasync Toolkit is a cross platform client-server toolkit for providing offline storage for cloud-based SQL and NoSQL data. The server component seamlessly integrates with ASP.NET Core and Entity Framework Core and the client component supports all modern client platforms, including Avalonia UI, MAUI, Project Uno, WinUI, and WPF. The Community Datasync Toolkit is a part of the Community Toolkit.

Roslynator is a set of code analysis tools for C#, powered by Roslyn.

OpenMod .NET Plugin Framework

WatsonTcp is the easiest way to build TCP-based clients and servers in C#.

Watson is the fastest, easiest way to build scalable RESTful web servers and services in C#.

Ant Design Blazor is a set of enterprise-class UI components based on Ant Design and Blazor. Following the Ant Design specification, we developed this Blazor Components library that contains a set of high quality components and demos for building rich, interactive user interfaces.

ASP.NET Ajax Control Toolkit contains a rich set of controls that you can use to build highly responsive and interactive Ajax-enabled Web applications. The Ajax Control Toolkit contains more than 40 controls, including the AutoComplete, CollapsiblePanel, ColorPicker, MaskedEdit, Calendar, Accordion, HTML Editor Extender, and Watermark controls. Using the Ajax Control Toolkit, you can build Ajax-enabled ASP.NET Web Forms applications by dragging-and-dropping Toolkit controls from the Visual Studio Toolbox onto an ASP.NET Web Forms page. DevExpress is now maintaining the ASP.NET AJAX Control Toolkit.

This is an open-source version of Telerik UI for Universal Windows Platform (UWP) by Progress

The "Asp" project, more formally known as ASP.NET API Versioning, gives you a powerful, but easy-to-use method for adding API versioning semantics to your new and existing REST services built with ASP.NET. The API versioning extensions define simple metadata attributes and conventions that you use to describe which API versions are implemented by your services. You don't need to learn any new routing concepts or change the way you implement your services in ASP.NET today.

Specialized .NET Streams, pipes, and extensions for full duplex in-proc communication, web sockets, and multiplexing.