Lucidchart vs Excalidraw: What are the differences?
Lucidchart: Collaborative diagramming solution for your entire organization. Solution for visual communication. Create online flowcharts, diagrams, UML sketches, and ER models; Excalidraw: Virtual whiteboard for sketching hand-drawn like diagrams. It is a whiteboard tool that lets you easily sketch diagrams with a hand-drawn feel.
Lucidchart and Excalidraw can be primarily classified as "Diagramming" tools.
Excalidraw is an open source tool with 9.24K GitHub stars and 619 GitHub forks. Here's a link to Excalidraw's open source repository on GitHub.