// the find
dotnet/aspnetcore
ASP.NET Core is a cross-platform .NET framework for building modern cloud-based web applications on Windows, Mac, or Linux.
The source repository for ASP.NET Core — the web framework that ships with .NET. This is where Kestrel, Blazor, SignalR, Razor Pages, minimal APIs, and the middleware pipeline live. If you're a .NET web developer, this is the upstream for everything you use daily.
Active daily commits with a clear public roadmap and weekly community standup — you can actually track what's changing and why. The modular architecture means you can read just Kestrel or just the routing layer without drowning in the whole codebase. Benchmarks are first-class citizens with a dedicated pipeline and public results, so perf regressions get caught before release. The contributor tooling is unusually good for a repo this size: devcontainer, detailed build-from-source docs, area owners listed, and a triage process that's actually documented.
The repo is enormous — the directory tree is thousands of files across Blazor, SignalR, Identity, gRPC, and more, which makes finding the right place to start a contribution non-trivial even with good docs. Build times from source are long and the eng/common Arcade scripts are a layer of abstraction that breaks in opaque ways when something goes wrong. The quarantined tests directory is a quiet admission that flaky tests are a persistent problem — if you're trying to run the full suite locally, expect pain. Blazor's two rendering models (Server vs WebAssembly vs the new unified model) have overlapping but subtly different APIs that still cause confusion in both the codebase and the docs.