Lectrix

Lectix is:

1. Free, and private. Open-source, with no paid version or paid features, no account and no data collected. Lectrix works offline and goes online only to check for a new version, which Settings can turn off.

2. The same app on Windows, macOS and Linux. One interface and the same tools on all three systems; none of them is treated as second-class.

3. Lightweight and fast. The Windows installer is under 8 MB. On a mid-range laptop the window is up in a tenth of a second, and the first page of a 1,000-page book in another tenth.

4. Designed with care. A modern, well thought-out interface that takes the pain out of the part of a PDF app you meet most: everyday use. Choose a light or a dark theme, dock the annotation toolbar or let it float at any edge of the pages, pick the quick tools offered for selected text, move the side panels between the two panes, and change any keyboard shortcut.

5. Careful with your files. Saving never leaves a half-written file behind, and a copy of your unsaved changes, kept every two minutes, is offered back after a crash.