Open PDF Studio is a new free software PDF editor and annotator from the OpenAEC Foundation. Licensed under the LGPL-3.0, it targets Windows, macOS, Linux, and Android, and is built with Tauri 2, SolidJS, PDF.js, and pdf-lib. The project describes itself as a lightweight native app without subscriptions, telemetry, or bloatware.
The feature list is unusually relevant to project documentation workflows: text markup, drawing and shape annotations, stamps, signatures, redaction, page insertion and reordering, PDF merging, bookmarks, forms, printing, export to images, and XFDF annotation import/export. Measurement tools are also included, with distance, area, perimeter, scale calibration, and object snapping.
Open PDF Studio is early, but it is already packaged through GitHub releases, Snap, Debian/Ubuntu packages, AppImage, macOS DMG, Windows installer, and Android APK. If it matures, it could become a useful free software option for reviewing drawings, specifications, submittals, markups, and other PDF-heavy coordination material.