BOUML might be a bit more popular than UMLet. We know about 1 link to it since March 2021 and only 1 link to UMLet. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
I like Umlet. It is a GUI drawing tool, but is not overbearing. Since I like to abuse the details of UML graphical notation, Umlet lets me type anything in a class "box" I like. Source: 12 months ago
Markdeep[0] from Casual Effects has a way of drawing diagrams using extended markdown. I used it to write this document with two diagrams: https://loan-free-ed.neocities.org Other tool I like are PlanetUML[1], BoUML[2] and Modellio[3](it is very heavy though on system resources!) [0] https://casual-effects.com/markdeep [1] https://plantuml.com [2] https://bouml.fr [3] https://www.modelio.org. - Source: Hacker News / about 3 years ago
draw.io - Online diagramming application
Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
StarUML - StarUML
Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.
UML Designer - UML Designer provides a set of common diagrams to work with UML 2.5 models.