yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
Freshservice - Freshservice: the one-stop cloud solution for all your IT management needs.
draw.io - Online diagramming application
Atera - Atera’s all-in-one platform enables IT professionals to gain access, visibility, and control over all their networks and devices from anywhere, so they can work smarter and light years faster.
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.
NinjaOne - NinjaOne (Formerly NinjaRMM) provides remote monitoring and management software that combines powerful functionality with a fast, modern UI. Easily remediate IT issues, automate common tasks, and support end-users with powerful IT management tools.