TaxJar - TaxJar simplifies sales tax filing for eCommerce sellers.
draw.io - Online diagramming application
Thomson Reuters ONESOURCE - ONESOURCE tax software and solutions synchronize every aspect of your work and link international, country, state and local tax laws.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Vertex Cloud - Vertex Cloud offers sales and use tax automation solutions.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.