The problem?
Collaborating on documents, especially PDFs is still a huge hassle. PDFs are everywhere (research, contracts, reports, briefs), but collaboration is just not easy:
We had endless email chains with renamed versions (pdfDoc\_v2\_final\_final\_version.pdf, anyone?)
The comments were lost across tools.
Review workflows were so hard that we had another tool tracking other tools' output and even that became a mess to navigate.
We were experiencing this first-hand and went searching for a good solution... but everything we found was either:
Clunky or bloated
Behind enterprise licenses
Or just plain slow
So we decided to build it ourselves.
We’ve been quietly building Theōros(https://theoros.app). This is a collaborative document annotation tool designed for analysts, researchers, students, deep readers and anybody who has to work a lot with documents.
It’s like Figma for PDFs: real-time collaboration, synced page navigation, highlights, and margin notes across multiple documents.
Perfect for reviewers, study groups, research teams, or solo readers who want to leave a structured trail of thoughts.
It also comes with built-in AI that can answer questions and provide citations directly from the document itself. No more context switching or CTRL+F hunts. The AI actually understands the text you’re working with but doesn't get in your way.
We’ve prioritized UX from the ground up. The entire interface is fully navigable via keyboard for fast, efficient workflows.
We are opening a waitlist right now. Head over to Theōros (https://theoros.app) and join.
