pdf-annotation

PDF++: the most Obsidian-native PDF annotation & viewing tool ever. Comes with optional Vim keybindings.

An open source PDF viewer/editor with it's own blazing fast rust engine

Open Paper is a workbench for managing your research library. Read, annotate, and understand your papers all in one place. Use an AI assistant to conduct your literature review.

An annotation extension based on the PDF.js viewer. Supporting the editing of existing PDF file annotations, posting comments, replying, submitting annotation data, and loading for further editing. 一个基于 PDF.js 阅读器的批注扩展，支持对现有 PDF 文件批注的编辑、发布评论、回复、提交批注数据以及加载后续编辑功能。

Annotation layer for pdf.js

Backchannel brings the internet's conversations into whatever you're reading. It blends Hacker News, Bluesky, Reddit, and more into a single discussion thread beside any page, then brings those sources together into a blended front page when you're ready to find something new.

The Google Scholar PDF Reader browser extension, now with annotations!

A drawing, note-taking and book annotation app for KOReader, built for e-ink: drawings with layers, notebooks with handwriting to text, ink on EPUB, MOBI, PDF and comics that follows the text, and stylus support with palm rejection and pen pressure.

Modular multi-screen pdf presentation viewer

Alfred Workflow to extract annotations from PDF files.

C# and VB.NET samples for Docotic.Pdf library

MAINTENANCE-MODE: Simple "digitial paper" for note taking and PDF annotation. Heavily inspired by Xournal.

Free, open-source native macOS PDF reader and Markdown editor. Distraction-free reading, annotation and live-preview writing.

📄 Set of modern React components for PDF highlighting

A React component for annotating PDF, powered by PDF.js and RecogitoJS

React PDF viewer & annotator SDK — highlight, markup, ink, shape, stamp and signature annotations with comments, review workflow and collaborative permissions. Export to PDF/Excel. React PDF 查看与批注 SDK， 支持高亮、笔迹、图形、印章、签名、评论审阅与协作权限。

A PDF reader and annotator for Windows and macOS, built for research. Free, MIT-licensed, and offline unless you ask a question.

Handwrite with any stylus in real, paginated notebooks: Apple Pencil, Android tablet pens, or a pen on Windows, macOS and Linux. Paper templates, shapes that snap, PDFs and pictures, all kept as plain files in your own vault.

Xivly — papers without distraction. A calm, open-source PDF reader for arXiv & research papers: annotate, organize, hover-preview citations & figures. Mac, Windows, Linux, web.

让你的 AI Agent 按阅读目标给论文 PDF 画重点、写导师式边注，标注写进 PDF，在 Zotero 里直接看。