draw.io - Online diagramming application
MATLAB - A high-level language and interactive environment for numerical computation, visualization, and programming
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.
Wolfram Mathematica - Mathematica has characterized the cutting edge in specialized processing—and gave the chief calculation environment to a large number of pioneers, instructors, understudies, and others around the globe.
Dot Chart - Dot Chart is simple and quick online process mapping system.
Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.