Teams that rely on proprietary design and whiteboard tools often find their files stored in a vendor's cloud, accessible only through that vendor's app and terms. Moving diagrams, wireframes or notes out later can mean exporting partial formats, losing links and rebuilding work by hand. Open-source tools reduce this risk because you can inspect the code, self-host where the project supports it, and keep your files in formats you control. Several categories in the Stackora catalog cover this need: sketching whiteboards, flowchart editors, design platforms and note-taking apps.

The lock-in problem in practice

The usual pattern looks like this:

  • Diagrams and boards are saved only in a hosted workspace.
  • Sharing and collaboration depend on a single vendor's service.
  • Offline access is limited or absent.
  • Exporting a whole project in a usable form is slow or incomplete.

For developers and IT teams, this creates a dependency that is hard to audit and hard to exit. The fix is not to avoid cloud tools altogether, but to choose tools whose source is public and whose data can be stored locally or on infrastructure you run.

Open-source options by use case

Whiteboards and sketches

Excalidraw is an open-source virtual whiteboard for hand-drawn style diagrams and sketches. It supports real-time collaboration and end-to-end encryption, and is published under the MIT license. It is a good fit for quick architecture sketches and workshop boards.

If you want to build a whiteboard into your own product, tldraw is an open-source infinite canvas SDK for React. It lets developers build whiteboard, diagramming and collaborative drawing apps instead of renting one.

Flowcharts and diagrams

drawio-desktop is an open-source Electron desktop app for creating flowcharts and diagrams offline. It wraps the core draw.io editor and is licensed under GPL-3.0. Because it runs offline, diagrams can stay on the local machine.

For node-based interfaces, graph editors and flowcharts inside your own application, xyflow provides React Flow and Svelte Flow under the MIT license.

Design and prototyping

Penpot is an open-source web design and prototyping platform for product teams. It offers real-time collaboration, design tokens and self-hosting options, and is licensed under MPL-2.0. It is the most direct replacement for a proprietary design suite in the set.

For building websites and templates visually, GrapesJS is a free, open-source web builder framework for HTML templates, usable for sites, newsletters and apps.

Notes and knowledge bases

AppFlowy is an open-source desktop note-taking and knowledge-base app for documents, wikis and projects. It includes AI features and gives you local control of your data, under the AGPL-3.0 license.

Visual programming and component work

Blockly is an open-source JavaScript library that adds a drag-and-drop visual code editor to web apps, so users can build programs from blocks. Storybook is a CLI-driven tool for building, documenting and testing frontend components in isolation, which helps design and engineering teams share one set of UI components.

Customer conversations that often sit beside diagrams

If your design reviews are tied to customer feedback, Chatwoot is an open-source, self-hosted support platform that unifies live chat, email and social channels in one inbox.

How to start

  1. List the work that currently lives in proprietary tools: sketches, flowcharts, UI designs, notes.
  2. Match each category to one tool. For quick sketches, try Excalidraw. For offline diagrams, try drawio-desktop. For full design work, evaluate Penpot.
  3. Test export and import with a real file before migrating. Confirm that you can open your data without the vendor's service.
  4. Decide where data should live. Local desktop apps keep files on your machine; self-hostable web apps keep them on your servers.
  5. Document the chosen tools and licenses so your IT team can review them. Check each license, since Excalidraw and xyflow are MIT, Penpot is MPL-2.0, drawio-desktop is GPL-3.0 and AppFlowy is AGPL-3.0.

Browse the web apps, developer tools and libraries sections of the catalog to compare more options, or see the Desktop Apps category for offline tools.

Recommendation

For most teams, start with two tools: Excalidraw for collaborative sketching and drawio-desktop for offline diagrams. Add Penpot if you need full design and prototyping, and choose a library such as tldraw or xyflow only if you are building these capabilities into your own product. Keeping files in open formats and on infrastructure you control is the practical way to avoid being locked into a single cloud vendor.