Excalidraw is a popular open-source, hand-drawn diagramming tool, created mainly to provide users with a simple yet powerful sketching option on their computers.

Here is a brief overview of the repository:

• Repository name: excalidraw/excalidraw
• Description: Excalidraw is a virtual collaborative whiteboard tool that lets you easily sketch diagrams with a hand-drawn feel.
• Programming Language: The predominant language used in this repository is TypeScript.
• License: The project is licensed under the MIT License.

Notable repository features:

1. Collaboration: You can collaborate in real time with others.
2. Sharing: You can share drawings with others via a link.
3. Privacy: The application doesn't collect any personal data unless you explicitly decide to share it.

With over 20k stars and more than 300 contributors, the repository is quite active and maintained regularly.

Sample Markdown: ```markdown

excalidraw/excalidraw

Excalidraw is a virtual collaborative whiteboard tool that lets you easily sketch diagrams that have a hand-drawn feel to them.

• Main Language: TypeScript
• License: MIT

Features

• Real-time collaboration
• Sharing via link
• Privacy focused ``` Please note that the information might change as the repository is updated. For the most accurate information, it'd be best to visit the official Excalidraw GitHub repository.