Highly Performant & Scalable Ultima Online Server Emulator https://www.modernuo.com
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Kamron Batman 1391c563fe
chore: Adds AI instructions and SKILLs for ModernUO codebase (#2347)
Summary

  - Adds CLAUDE.md at repo root with 14 terse code audit rules (always loaded, low token cost)
  - Adds pointer files for other AI tools: AGENTS.md (Codex), GEMINI.md, .github/COPILOT-INSTRUCTIONS.md (Copilot), .cursorrules (Cursor) — all redirect to CLAUDE.md as single source of truth
  - Gitignores /.claude so personal AI config isn't distributed
  - Moves Claude skills to dev-docs/claude-skills/ (opt-in, not auto-loaded)
  - Adds 14 dev-docs covering codebase conventions

  Code Audit Rules (in CLAUDE.md)

  1. LINQ tiered rules (Tier 1 free, Tier 2 warm, Tier 3 forbidden)
  2. No Console.WriteLine — use LogFactory.GetLogger()
  3. No concurrency primitives in game code
  4. No World.Mobiles/World.Items iteration
  5. Clean up refs in OnDelete()/OnAfterDelete()
  6. Cancel timers in OnDelete()/OnAfterDelete()
  7. STArrayPool<T>.Shared not ArrayPool<T>.Shared
  8. PooledRefList<T> not new List<T>() on hot paths
  9. Serialization: partial class, [Constructible], no serialized TimerExecutionToken
  10. No Task.Run/new Thread() in game code
  11. Never assume era — ask which expansion
  12. _camelCase fields, PascalCase properties/methods
  13. No empty gumps — use DisplayTo() pattern
  14. PropertyList string literals must be {} holes, cliloc-as-argument uses :#
2026-03-01 11:42:19 -08:00
.config feat: Adds SerializableFieldChanged option (#2324) 2026-02-01 21:28:26 -08:00
.github chore: Adds AI instructions and SKILLs for ModernUO codebase (#2347) 2026-03-01 11:42:19 -08:00
dev-docs chore: Adds AI instructions and SKILLs for ModernUO codebase (#2347) 2026-03-01 11:42:19 -08:00
Distribution/Data feat: Adds Network Packet Documentation (#2302) 2026-01-01 17:52:56 -08:00
docs chore: Fixes 0x78 and min client version for packets.html (#2322) 2026-01-31 10:58:13 -08:00
Projects feat: Implements passive Detect Hidden mechanics (#2342) 2026-02-28 11:24:49 -08:00
.cursorrules chore: Adds AI instructions and SKILLs for ModernUO codebase (#2347) 2026-03-01 11:42:19 -08:00
.editorconfig chore(docs): Adds UnmanagedDataReader & BinaryFileReader documentation (#1968) 2024-10-01 17:07:51 -07:00
.gitattributes fix: Adds migration checks to CICD, updates dependencies, adds Fedora 37, alpine 3.17 support (#1309) 2022-12-22 12:12:47 -08:00
.gitignore chore: Adds AI instructions and SKILLs for ModernUO codebase (#2347) 2026-03-01 11:42:19 -08:00
AGENTS.md chore: Adds AI instructions and SKILLs for ModernUO codebase (#2347) 2026-03-01 11:42:19 -08:00
azure-pipelines.yml feat: Adds .NET 10 / C# 14 support. (#2258) 2025-11-11 11:26:34 -08:00
CLAUDE.md chore: Adds AI instructions and SKILLs for ModernUO codebase (#2347) 2026-03-01 11:42:19 -08:00
CODE_OF_CONDUCT.md Create CODE_OF_CONDUCT.md 2020-05-05 08:51:39 -07:00
CONTRIBUTING.md chore(license): Removes CLA requirement. All contributors moving forward will retain copyright. (#2038) 2024-12-31 02:52:58 -08:00
Directory.Build.props feat: Adds .NET 10 / C# 14 support. (#2258) 2025-11-11 11:26:34 -08:00
FAQ.md docs: Updates FAQ for time zone issues. (#1368) 2023-03-10 00:18:36 -08:00
GEMINI.md chore: Adds AI instructions and SKILLs for ModernUO codebase (#2347) 2026-03-01 11:42:19 -08:00
global.json feat: Adds .NET 10 / C# 14 support. (#2258) 2025-11-11 11:26:34 -08:00
LICENSE Fixes more line ending issues (#267) 2020-09-27 13:54:56 -07:00
mkdocs.yml chore: Fixes github pages (#2303) 2026-01-01 19:35:35 -08:00
ModernUO.sln fix: Updates Visual Studio version in solution file to Visual Studio 2026 (#2285) 2025-12-01 14:46:36 -08:00
publish.cmd fix: Fixes publishing (#1808) 2024-05-31 12:59:59 -07:00
publish.sh fix: Fixes publishing (#1808) 2024-05-31 12:59:59 -07:00
README.md feat: Upgrades networking to use io_uring. (#2315) 2026-02-01 16:02:32 -08:00
rider-settings.zip Cleanup/Housekeeping (#242) 2020-09-12 15:31:21 -07:00
Rules.ruleset chore(docs): Adds UnmanagedDataReader & BinaryFileReader documentation (#1968) 2024-10-01 17:07:51 -07:00
SPONSORS.md chore: Updates readme files (#2247) 2025-07-27 11:04:32 -07:00
stylecop.json Updates formatting rules (#199) 2020-08-25 18:00:51 -07:00
THIRD-PARTY-NOTICES chore: Updates 3rd party notices (#1042) 2022-06-01 09:42:11 -07:00
version.json feat: Upgrades networking to use io_uring. (#2315) 2026-02-01 16:02:32 -08:00

ModernUO - Ultima Online Server Emulator for the modern era!

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Ultima Online Server Emulator for the modern era!

GitHub license GitHub stars GitHub issues
GitHub build Azure Pipelines build

Requirements

Supported Operating Systems

Windows 10/11/2012/2016/2019/2022/2025 MacOS 14+ Debian 12+ Ubuntu 22+ LTS
Alpine 3.22+ Fedora 42+ RedHat 9+ CentOS Stream 9+ openSUSE 15.6+ SUSE Enterprise 15 SP6 Linux Mint 21+ Arch

Required Frameworks

All Operating Systems

.NET

Windows

VC++ Redistributable v14

Development

git .NET

Supported IDEs

Jetbrains Rider 2025.3+ space VSCode space Visual Studio 2026

Getting Started

  • Install prerequisite requirements
  • Clone this repository (or download the latest):
    • git clone https://github.com/modernuo/ModernUO.git
  • Open ModernUO.sln to start developing

Building/Publishing

  • Run ./publish.cmd [release|debug (default: release)] [os] [arch (default: x64)]

Linux Prerequisites

Fedora, CentOS, RHEL, etc

dnf upgrade --refresh -y
# CentOS does not come with EPEL enabled
dnf install -y epel-release epel-next-release
dnf install -y findutils libicu libdeflate-devel zstd libargon2-devel liburing-devel

Ubuntu, Debian, etc

apt-get update -y
apt-get install -y libicu-dev libdeflate-dev zstd libargon2-dev liburing-dev

OSX Requirements

brew install icu4c libdeflate zstd argon2

Running the Server

  • Follow the publish instructions
  • Run ModernUO.exe or dotnet ModernUO.dll from the Distribution directory

Troubleshooting / FAQ

Want to sponsor?

Thank you for supporting us! You can find out how by visiting the sponsors page.

Collaborators

Kamron Batman Mark1145

Thanks

  • RunUO Team & Community
  • Voxpire, the ServUO Team & Community
  • Karasho, Jaedan and the ClassicUO Community



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