Ibis is a federated encyclopedia (wiki) platform built with Rust. It is a full-stack web application using Leptos for the frontend (SSR + WASM hydration) and Axum for the backend API, with PostgreSQL as the database via Diesel ORM. Its primary purpose is to provide a decentralized, collaborative knowledge base where users can create, edit, and discuss articles, with changes synchronized across independent instances using the ActivityPub protocol. The architecture is a well-structured monorepo with distinct crates for the backend server, frontend pages, database logic, federation logic, API client, and markdown processing. The system features a sophisticated diff-based version control system for articles, complete with three-way merge conflict resolution, nested comments, a comprehensive notification system (in-app and email), OAuth authentication, and internationalization support. The codebase demonstrates high craftsmanship in its ActivityPub implementation, which cleanly models objects, activities, and collections, and in its custom markdown parser that supports LaTeX, table of contents, spoilers, and footnotes. The frontend components are well-abstracted, and the API client is designed for reuse across different contexts. While actively maintained, the project shows some signs of technical drift, including migration inconsistencies, a few known performance inefficiencies, and the use of experimental Rust features that may impact long-term maintainability.