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
LibreOffice Draw is a comprehensive vector graphics editor with robust features suitable for complex projects and collaboration, while Diagram Designer focuses on simplicity and ease of use for basic diagramming tasks. The former offers a broader range of functionalities, whereas the latter is more lightweight and user-friendly for straightforward diagram creation.