{
  "added_at": "2026-11-09",
  "additional_evidence_urls": [
    "https://github.com/xu4-engine/u4/blob/6a7ee3d0079cfdc1c8fb9ba7a3c710a957155a71/doc/FileFormats.md"
  ],
  "category": "reconstruction-cases",
  "class": "game",
  "description_en": "XU4 recreates Ultima IV for modern systems while loading the original DOS game's data at runtime. Its implementation supports original EGA and upgraded VGA graphics, and its documentation maps file structures such as SHAPES.EGA.",
  "description_zh": "XU4 为现代系统重建 Ultima IV，并在运行时读取原版 DOS 游戏数据。它支持原版 EGA 与升级版 VGA 画面，文档还记录了 SHAPES.EGA 等文件结构。",
  "entry_url": "https://awesomerea.org/resources/xu4-ultima-iv-case/",
  "entry_url_zh": "https://awesomerea.org/zh/resources/xu4-ultima-iv-case/",
  "evidence_class": 2,
  "evidence_status": "observed",
  "evidence_url": "https://github.com/xu4-engine/u4/blob/6a7ee3d0079cfdc1c8fb9ba7a3c710a957155a71/README.md",
  "group": "cases",
  "id": "xu4-ultima-iv-case",
  "json_url": "https://awesomerea.org/resources/xu4-ultima-iv-case/record.json",
  "kind": "case-study",
  "markdown_url": "https://awesomerea.org/resources/xu4-ultima-iv-case/index.md",
  "markdown_url_zh": "https://awesomerea.org/zh/resources/xu4-ultima-iv-case/index.md",
  "name": "XU4: a reconstruction of Ultima IV",
  "name_zh": "XU4：Ultima IV 游戏重建",
  "reconstruction_method": "engine-reimplementation",
  "record_type": "resource",
  "relationship": "independent-reconstruction",
  "requirement_facets": [
    "prerequisites",
    "scope",
    "license"
  ],
  "requirements": [
    "A copy of Ultima IV for DOS is required for runtime data.",
    "Linux is the primary development platform; Windows builds are also described.",
    "GPL-3.0 license."
  ],
  "requirements_zh": [
    "运行时需要 Ultima IV 的 DOS 版数据。",
    "主要开发平台是 Linux，文档也说明了 Windows 构建。",
    "采用 GPL-3.0 许可证。"
  ],
  "scope": "unknown",
  "targets": [
    "game"
  ],
  "url": "https://github.com/xu4-engine/u4",
  "verification": "source-reviewed",
  "verified_at": "2026-11-06"
}