推荐一个白板开源程序：Excalidraw

Excalidraw is a whiteboard tool that lets you easily sketch diagrams that have a hand-drawn feel to them.
Excalidraw是一个白板工具，可以让你轻松地绘制出手绘的图表。
An open source virtual hand-drawn style whiteboard.
Collaborative and end-to-end encrypted.
一个开源的虚拟手绘风格白板.协作和端到端加密。

Features
The Excalidraw editor (npm package) supports:

Free & open-source.
Infinite, canvas-based whiteboard.
Hand-drawn like style.
Dark mode.
Customizable.
Image support.
Shape libraries support.
Localization (i18n) support.
Export to PNG, SVG & clipboard.
Open format - export drawings as an .excalidraw json file.
Wide range of tools - rectangle, circle, diamond, arrow, line, free-draw, eraser...
Arrow-binding & labeled arrows.
Undo / Redo.
Zoom and panning support.
Github地址：https://github.com/excalidraw/excalidraw

搭建一个：https://draw.lanol.cn