Posted by squidleon 16 hours ago
What it does today: - Full packet layer for the classic UO client (login, movement, items, mobiles) - Lua scripting for item behaviors (double-click a potion, open a door — all defined in Lua, no C# recompile) - Spatial world partitioned into sectors with delta sync (only sends packets for new sectors when crossing boundaries) - Snapshot-based persistence with MessagePack - Source generators for automatic DI wiring, packet handler registration, and Lua module exposure - NativeAOT support — the server compiles to a single native binary - Embedded HTTP admin API + React management UI - Auto-generated doors from map statics (same algorithm as ModernUO/RunUO)
Tech stack: .NET 10, NativeAOT, NLua, MessagePack, DryIoc, Kestrel
What's missing: Combat, skills, weather integration, NPC AI. This is still early — the focus so far has been on getting the architecture right so adding those systems doesn't require rewiring everything.
Why not just use ModernUO/RunUO? Those are mature and battle-tested. I started this because I wanted to rethink the architecture from scratch: strict network/domain separation, event-driven game loop, no inheritance-heavy item hierarchies, and Lua for rapid iteration on game logic without recompiling.
Are there UO clients besides the official one?
You're touching on a real pain point. Right now the Lua boundary does show measurable overhead under load, especially with per-tick callbacks across many entities (doors, spawners, etc.). MoonSharp's interop cost adds up when you're calling into Lua thousands of times per tick.
I'm actively looking at batching script invocations per tick and capping the budget so a heavy script wave can't blow up tail latency. The goal is to keep the game loop deterministic if Lua eats too much of the tick budget, defer the rest to the next tick rather than letting the whole loop stall.
It's one of those problems where the architecture gives you a clean place to solve it (the boundary is explicit, so you can meter it), but the solution still needs work. Appreciate you calling it out — good toknow others think about the same tradeoffs.