Librum

Librum is a native, cross-platform e-book reader and personal library manager that lets users organize, read and sync books across devices. It provides an integrated bookstore, highlighting and annotation tools, and optional AI-assisted lookups and summaries for text within books. (librumreader.com)

Key Features

• Modern native reader with text search, highlighting and bookmarking.
• Supports major formats: PDF, EPUB, CBZ, FB2, MOBI, XPS, TIFF and image collections.
• Personalized online library with collections, tags, metadata editing and cross-device sync.
• Free in-app bookstore (claimed ~70,000 books) and reading statistics.
• AI integration for explanations/summaries and quick lookups (limited free usage per account).
• Customizable interface, keyboard shortcuts and theme support.
• Build tooling: CMake-based build with Qt (Qt 6.5 recommended) and platform-specific instructions for Linux, Windows and macOS. (github.com)

Use Cases

• Personal library management and daily reading across desktop platforms (Windows, Linux, macOS).
• Syncing reading progress, highlights and metadata between devices via Librum’s cloud (or self-hosting with Librum-Server).
• Power users and packagers building from source, integrating into distributions or deploying as Flatpak for Linux. (github.com)

Limitations and Considerations

• Some features are marked "Coming Soon" in the project (mobile clients, TTS, advanced note-taking and some personalized stats).
• Community reports have noted occasional platform-specific issues (e.g., Flatpak/permission and image library mismatches causing crashes in older distributions); users should test distribution builds and check issues before wide deployment. (github.com)

Librum is a GPL-licensed open-source project intended for users who prefer a native, Qt-based reading experience with optional cloud sync and self-hosting paths. It’s suitable for both casual readers and power users who want to compile, package or self-host their library server. (github.com)