Ageratum

Guidebook mods on NeoForge can use Ageratum to display documentation inside the game. It renders a Markdown dialect with ATX and Setext headings, paragraphs with line breaks, ordered, unordered and task lists with multi-level nesting, blockquotes, fenced and indented code blocks, horizontal rules and tables with alignment settings. Guides can be translated through its i18n localization support, and the library exists so that other mods can offer documentation in the game.

Guide authors can extend the format with two block-level extension syntaxes and custom components. A recipe extension renders crafting recipes directly inside a document, and a structure extension renders a top-down block preview and a bounded NBT tree for .nbt files. Interactive text can show a hover tooltip or run an action on click, and several styles can be combined on the same text. Inline style parsers are registered through a registry key, and a client command opens guides, with tab completion for namespaces and file names.

Ageratum is client required and server optional, so players need it to read guides while the server can add it for extra features. It is open source under the GNU Lesser General Public License v3.0 only and is published for NeoForge 1.21.1 and 26.1.2.