Xournal++

Xournal++ is a free, open-source note-taking app built around the pen. It is made for handwritten notes, sketching and PDF annotation: import a PDF, write straight on it, highlight, drop in text or shapes, and export the result. Students annotate lecture slides with it, teachers grade assignments, researchers mark up papers, and anyone with a stylus or convertible laptop gets a digital notebook that does not lock their notes in someone else's cloud.

The ink engine is the main event: smooth, low-latency strokes with pressure sensitivity on graphics tablets and pens, so handwriting and diagrams feel like paper rather than a mouse exercise. Notes live in layers, which sounds like a small thing until you use it - keep a draft layer under a clean layer, hide your annotations while presenting, or toggle a solutions layer on a worksheet. Shape recognition tidies rough circles, rectangles and arrows into clean geometry, and LaTeX integration typesets proper equations inline with your handwriting.

One feature sells it to a lot of students on its own: audio recording synced to your notes. Record the lecture while you write, then tap any stroke later to jump to whatever was being said at that exact moment. Paper backgrounds come in blank, lined, dotted and graph, with custom templates if you want your own, and the toolbar, pens and keyboard shortcuts are all configurable. A Lua-based plugin system covers the remaining gaps, and because sessions autosave, a crash costs you seconds of work rather than an afternoon.

Xournal++ runs on Windows, macOS and Linux, is GPL-2.0 open source, and the current stable release is 1.3.8 (September 2026). It is a community fork of the older Xournal project, rewritten in C++ and actively maintained. Files save in the native .xopp format and export to PDF, PNG and SVG, so sharing and archiving stay easy whatever your correspondent uses.

The honest trade-offs: there is no built-in cloud sync and no mobile app - your files stay local, and syncing means pointing your own service at the right folder. The GTK interface feels more utilitarian than polished commercial apps like GoodNotes, and stylus setup on some tablets takes a little configuration. It is also a notebook, not a word processor; long typed documents are not its job. For pen-first note-taking and PDF markup without a subscription, though, it is the standard answer on Linux and a very good one everywhere else.