REDox

RE:Dox is a .NET library from CAPCOM for reading, editing and converting structured data: JSON, JSON5, CBOR, MessagePack and INI, with TOML, XML, HTML and CSV in preview. Everything lands in one compact token model, so the same code handles every format. It's a piece of REX, CAPCOM's next-generation engine tech, released under Apache 2.0.

It's a NuGet package (dotnet add package CAPCOM.REDox), so there's nothing to host. CAPCOM's own benchmarks show up to about 1.8x faster deserialization and 1.6x faster serialization than System.Text.Json, with much less memory allocated, though the README warns those aren't universal guarantees. Compatibility layers for System.Text.Json and Newtonsoft.Json let you try it without rewriting everything.

Teams on .NET 10 with heavy serialization work (game tools, data pipelines, config-heavy apps) should benchmark it against their real payloads. Everyone else is fine on System.Text.Json. Game developers drawn in by the CAPCOM name should know this isn't engine code, just a serializer.

The catch: it requires .NET 10, which rules out .NET 8 LTS shops and likely Unity. Half of its 12 packages, including both compatibility layers, are preview, and v1.0.1 shipped breaking changes five days after v1.0.0. The GitHub org isn't verified, though capcom.com commit emails and CAPCOM's own conference page back it up.