Sure, Visio is awesome.

But have you considered these open source alternatives?

They are free, self-hostable and community-driven.

Check by yourself: Excalidraw  Excalidraw , tldraw  tldraw , diagrams.net  Draw.io ,  D2 , LibreOffice  LibreOffice .

  1. So is Excalidraw Excalidraw

    Whiteboard for sketching hand-drawn like diagrams

    ★ 107.6K Diagram Whiteboard License: MIT

    An open source virtual hand-drawn style whiteboard. Collaborative and end-to-end encrypted.

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  2. So is tldraw tldraw

    Digital whiteboard with infinite canvas

    ★ 43K Diagram License: MIT

    Tldraw is a library for creating infinite canvas experiences in React. It's the software behind the digital whiteboard tldraw.com.

  3. So is diagrams.net Draw.io

    JavaScript, client-side editor for general diagramming

    ★ 57K Diagram License: Apache-2.0

    Browser-based diagramming components and applications.

    preview

  4. So is D2

    Turn text into diagrams

    ★ 21.9K Diagram License: MPL-2.0

    A modern diagram scripting language that turns text to diagrams.

    preview

  5. So is LibreOffice LibreOffice

    Office suite

    ★ 3.3K Office suite License: MPL-2.0

    LibreOffice is an integrated office suite based on copyleft licenses and compatible with most document formats and standards. Libreoffice is backed by The Document Foundation, which represents a large independent community of enterprises, developers and other volunteers moved by the common goal of bringing to the market the best software for personal productivity. LibreOffice is open source, and free to download, use and distribute.