GameNetworkingSockets vs Normcore

GameNetworkingSockets is a free BSD-3-Clause transport library for games that sends reliable and unreliable messages over UDP. It handles messages larger than the underlying MTU through fragmentation and reassembly, with retransmission for reliable messages. Packets use AES-GCM-256, while Curve25519 supports key exchange and certificate signatures. Peer-to-peer connections can use Google WebRTC ICE for NAT traversal, with an option to plug in a signaling service. Multiple message lanes can share one connection under strict priorities or weighted bandwidth rules. Included diagnostics simulate packet latency and loss and measure detailed statistics. The library is written in C++ and also exposes a plain C interface; third-party bindings are listed for C#, Go, and Rust. Build instructions cover Linux, Windows, macOS, and iOS. Steam is not required for the open-source library, but authentication, signaling, and Steam Datagram Relay remain Steam-only services. Higher-level entity serialization, delta encoding, and compression are not included.

Normcore is a networking solution for Unity multiplayer applications. It provides networked physics, persistent spaces, voice chat and XR support, with EasySync for synchronizing properties without code; that component can also be converted to a C# RealtimeComponent. Voice over IP and audio streaming can be added to a prefab using a Unity component. For Unity WebGL builds, it supports multiplayer and voice chat through WebRTC without code modifications. The service is aimed at desktop, console, mobile, VR, AR and WebGL projects, with game servers across cloud providers that select regions based on client latency. Normcore Private offers deployment on dedicated cloud servers or on-premises hardware, with support for custom server-side C# or C++ plugins. Its Public plan is free and includes 100 room hours and 120GB of bandwidth per month. Pro costs $49 a month and includes 10,000 room hours and 3TB of bandwidth. Unlimited costs $49 a month plus usage beyond 10,000 room hours and 3TB of bandwidth.