Diagram Designer is a vector graphics editor that allows you to create UML class diagrams, illustrations, flowcharts and slide shows. Developed by Meesoft
License: Free
Pencil Project is a versatile, open-source tool focused on UI/UX design with a broad range of templates, while Diagram Designer is a lightweight application ideal for creating vector-based diagrams. Pencil Project offers a more extensive feature set for designers, whereas Diagram Designer excels in speed and simplicity, making it suitable for quick diagram creation.