Visio 2007 Portable Verified
yEd is a powerful diagramming tool that runs on Java. Download the portable .jar version:
If you have a Microsoft 365 subscription, you may already have access to "Visio for the Web." It is lightweight, runs in the browser, and is the official successor to the legacy tools. visio 2007 portable verified
If you only need to view Visio 2007 (.vsd) files: yEd is a powerful diagramming tool that runs on Java