Sites like fluentvalidation.net

xUnit.net is an open source unit testing tool for C#, F# and Visual Basic, led by project lead Brad Wilson

A documentation site for FastEndpoints, an open-source .NET framework for building ASP.NET web API endpoints

NuGet is the central package repository and package manager for .NET, with package search, download statistics and client tools

Finbuckle MultiTenant, an open source .NET library for multi-tenancy with tenant resolution and per-tenant data isolation, by Andrew Lock's team

CodeOpinion, a blog and video channel on software architecture and design topics by Derek Comartin

Milan Jovanović's website selling .NET and software architecture courses, bundles, and blog-style engineering articles

Aurelia, a JavaScript web application framework created by Rob Eisenberg, with documentation, learning resources and community contributors

React Hook Form is a documentation site for a performant React form library, covering its API, TypeScript types and FAQs

Code with Steve, a blog on .NET and C# programming by Steve Gordon, a senior engineer at Elastic

Oh My Posh documentation for a cross-shell prompt theme engine that customizes terminal prompts, with installation and configuration guides

Khalid Abuhakmeh's blog on .NET, ASP.NET Core, C# and web development, written by a Duende Software engineer

Event-Driven, a blog, talks and guides by Oskar Dudycz on software architecture, Event Sourcing, CQRS and event-driven design

.NET nanoFramework, a free open-source platform for writing C# embedded applications on microcontrollers, with a news blog by Jos Simoes

Julio Casal's blog and YouTube channel on .NET backend development, Claude Code workflows, and a free API template

AsyncAPI, an open source initiative and specification with tools for defining and documenting event-driven architectures, under the Linux Foundation

Dev notes by Darío Kondratiuk, a Buenos Aires software developer, on browser automation, .NET and Puppeteer-Sharp

A .NET developer's blog and tutorial site by Mukesh Murugan covering C#, EF Core, Claude Code, Docker and system design

YogiHosting is a tutorial blog on ASP.NET Core, Blazor, jQuery, JavaScript and Entity Framework by a developer named Yogi

Vite, a frontend build tool and development server for modern web projects, documented by its core team

Ant Design, an open-source React UI component library and design system, with its release changelog and documentation

Eventuous, a documentation site for open-source Event Sourcing libraries in .NET and Go implementing DDD tactical patterns

A English-language podcast about the .NET and C# software development ecosystem, hosted by Richard Reis?

Shields.io is a service that generates concise, consistent badges for GitHub readmes and other web pages

Dokploy, a self-hosted platform for deploying containerized applications and databases across multiple servers

A personal blog by software engineer Steven Giesel on C#, .NET, software design and craftsmanship, with 338 posts

Personal blog by Mike Driscoll sharing Python tutorials, code samples and files from his Python Extension Building Network projects

Faker, a JavaScript library documentation site for generating realistic fake test data, with API reference, guide and modules

Six Labors is a company's website selling a .NET graphics library suite (ImageSharp, Drawing, Fonts) and its commercial licensing

Martin Kleppmann's personal website: blog, conference talks and publications on local-first software and distributed systems by a Cambridge academic

Vite, a frontend build tool and documentation site for modern web application development, with team and event pages

NgRx documentation and guides on reactive state management for Angular applications, covering the Global Store and SignalStore

Meziantou's blog by Gérald Barré on .NET, C# and web development, covering cancellation, async programming and developer tooling

OpenAPI TypeScript is a tool that converts OpenAPI 3.0 and 3.1 schemas into TypeScript types and type-safe fetch clients

Starship, a minimal, customizable shell prompt written in Rust, documented across multilingual pages and an FAQ

Tim Deschryver's blog on .NET, Angular, testing and agentic AI, with Belgian software engineer writing lessons learned from building software

TanStack, an open-source collection of headless web application libraries and tools, with a design system, blog and chat app

ESLint project website: documentation, playground and team pages for ESLint, the pluggable open-source JavaScript linter

A testing framework called Vitest, powered by Vite, with documentation for writing, mocking and configuring JavaScript tests

Documentation and project site for Passport.js, an authentication middleware library for Node.js applications

DB Browser for SQLite, an open source visual tool for creating, searching and editing SQLite and SQLCipher database files

TkDodo's blog: personal blog by Dominik Dorfmeister on JavaScript, React, TypeScript, TanStack Query, API design and open source

springdoc-openapi documentation for generating OpenAPI 3 specs and Swagger UI in Spring Boot applications