SIPSorcery is a mature, production-grade C# library for building real-time communication applications. It provides a complete SIP stack (UA, B2BUA, proxy), WebRTC peer connections with ICE/DTLS/SRTP/SCTP, RTP/RTCP streaming, STUN/TURN clients, and a pluggable media abstraction layer. The library is delivered as multiple NuGet packages (core, media abstractions, FFmpeg integration, Windows audio, VP8 codec, OpenAI Realtime client) and includes a CLI diagnostic tool (`sipsorcery`) for probing SIP, STUN, ICE, and TURN endpoints. The codebase is extensively tested with over 70 example projects covering SIP calling, WebRTC streaming, softphone, Unity integration, OpenAI voice agents, and cloud SFU/TURN services. Architecture follows interface-based design with clean separation of concerns: networking, signalling, media codecs, and application logic are modular and independently replaceable. The library demonstrates strong RFC conformance (SIP, WebRTC, STUN, ICE, SRTP) and includes performance benchmarks for SDP parsing, ICE candidate equality, and pixel format conversion. Notable reusable patterns include the `MediaFormatManager<T>` for codec negotiation, `LogFactory` abstraction, `RTPHeaderExtension` extensibility, `IceServerResolver` with async DNS, and the `BridgeGraph` for duplex media pipelines. However, the repository carries some technical debt: a large vendored C VP8/VP9 codec (libvpx) that is also ported to C# (`SIPSorcery.VP8`), auto-generated Cloudflare SFU client code, platform-specific FFmpeg interop, and AI-generated contributions that may require ongoing maintenance. The license includes a controversial restriction (BSD 3-Clause with a clause prohibiting use by entities contributing to Israeli occupation/genocide), which may cause compliance friction. Overall, SIPSorcery is a high-quality, feature-rich library with broad real-time communication capabilities, suitable for embedding in .NET applications needing VoIP, WebRTC, or media streaming.