If you are looking for a UML Diagram Editor Visio Alternative for Linux, Edraw should be what you need. It is a flexible and simple Visio alternative which helps you create UML diagrams easily on Linux.
Quick Overview of Linux UML Diagram Visio Alternative
As we all know, Visio software can not work on Linux system. As a cross-platform program, Edraw is one of the best Visio Alternative for creating UML diagrams that is fully compatible with Mac, Windows, Linux. Especially, Its built-in UML symbols and templates enable users to design more than nine types of UML diagram effortlessly.