
Diigo
The ultimate multi-tool for knowledge management, web annotation, and collaborative research.
Discover the best AI tools to help you annotate pdf documents.

Transform your handwritten notes into intelligent digital assets with AI-powered paper.

The fastest, most feature-rich alternative to Adobe Acrobat for precision document engineering.

The Original Online PDF Editor, Annotator, and Form Filler.

Streamline document workflows with secure PDF and eSign solutions.
DocHub simplifies document workflows by providing tools to edit, sign, and share PDFs online.

Trusted PDF tools enhanced with AI for creating, editing, and managing documents.

The industry-standard AEC collaboration and workflow automation platform for digital project delivery.

The ultimate open-source, AI-enhanced read-it-later solution for serious knowledge workers.

The ultimate AI-powered reference management system for modern research workflows.

A privacy-first, open-source platform for knowledge management and networked thought.