CentrED# is a complete C# rewrite of the original CentrED map editor for Ultima Online, created by kaczy93. It is the recommended modern alternative to both CentrED and CentrED+.

Features

• Client/Server map editor (same architecture as original CentrED)
• Cross-platform: Windows, Linux, macOS (including Apple Silicon)
• Built on .NET — no legacy FreePascal/Lazarus dependencies
• Active development (722 commits, v0.6.11.30 as of February 2026)
• MIT license
• Acknowledges work from ServUO, ModernUO, ClassicUO, and UOFiddler

Downloads

Latest release: v0.6.11.30 (February 7, 2026)

IRW (Item Resource Workshop) is a comprehensive resource editing tool for Ultima Online. It provides facilities for browsing, viewing, and editing various UO client resource files including items, art, and other game assets. The archive contains over 1,000 files including the full IRW application and associated UO data files. A substantial tool for serious client-side modding.

Download

• IRW (6.0 MB)

Archived from the UO FreeShard Community Tool Box (archive.org, 2019).

MultiList (Beta Release 5) is a viewer and browser for Ultima Online multi objects — structures composed of multiple tiles such as houses, castles, boats, and other complex in-game buildings. It allows previewing multi definitions from the multi.mul file, inspecting individual components, and exporting multi data. Useful for shard developers working with custom housing or structure designs.

Download

• MultiList Beta Release 5 (13 MB)

Archived from the UO FreeShard Community Tool Box (archive.org, 2019).

The Mythic Package Editor is an essential tool for working with UO’s modern UOP (Ultima Online Package) file format, introduced when Mythic Entertainment took over development. UOP files replaced the classic MUL format for storing game assets in newer client versions. This editor allows viewing, extracting, and modifying the contents of UOP packages including art, gumps, animations, and other game data. Version 1.2 includes a help file and dictionary for the package format. Critical for anyone working with Stygian Abyss or later client versions.

OrB Multi Template Manager 1.0 is a tool for managing and editing multi (building/structure) templates in Ultima Online. It provides an organized interface for creating, importing, and modifying multi definitions used for houses, castles, and other in-game structures. Part of the OrB (Orbsydia) suite of UO development tools.

Download

• OrB Multi Template Manager 1.0 (2.3 MB)

Archived from the UO FreeShard Community Tool Box (archive.org, 2019).

SUMP is a utility for working with Ultima Online MUL (data) files. It provides basic operations on UO’s proprietary asset files including viewing, extracting, and simple modifications to art, tile, and other game data files.

Download

• SUMP (33 KB)

Archived from the UO FreeShard Community Tool Box (archive.org, 2019).

Terra Mystica Tool (TMTool) is a terrain editing utility for Ultima Online maps. It provides tools for modifying land tiles, elevation data, and terrain textures in UO map files. A simpler alternative to full map editors like CentrED or WorldForge for quick terrain adjustments.

Download

• Terra Mystica Tool (247 KB)

Archived from the UO FreeShard Community Tool Box (archive.org, 2019).

Ultima Mapper is a comprehensive standalone map viewer and renderer for Ultima Online. It reads the UO client map data files and renders high-resolution, navigable map views of all facets (Felucca, Trammel, Ilshenar, Malas, Tokuno, Ter Mur). Supports zooming, panning, location search, coordinate display, and map image export. A substantial tool at 121 MB, useful for world exploration, shard documentation, and GM planning.

Downloads

• Ultima Mapper (121 MB)

Archived from the UO FreeShard Community Tool Box (archive.org, 2019).

A standalone hue (color palette) editor for Ultima Online’s hues.mul file. UO uses a system of 3,000+ color palettes (hues) that can be applied to any game graphic. This editor allows viewing, modifying, and creating custom hue entries — essential for shard developers who want custom-colored items, NPCs, or equipment not available in the default palette.

Download

• UO Hue Editor (228 KB)

Archived from the UO FreeShard Community Tool Box (archive.org, 2019).

UO Paperdoll is a tool for rendering and viewing Ultima Online character paperdoll images. It can display how equipment and clothing appear on the character sheet view, useful for testing custom art or verifying how new items look when equipped. Source code available (hosted on GitHub).

Download

• UO Paperdoll (8.7 KB)

Archived from the UO FreeShard Community Tool Box (archive.org, 2019).