Google Tag Manager - Google Tag Manager helps make tag management simple, easy and reliable by allowing marketers and webmasters to deploy website tags all in one place.
Dia - Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.
Tealium iQ Tag Management - Tealium is a dynamic platform that comes with a highly extensible iQ Tag Management system to manage mission-critical technologies with ease and comfort.
draw.io - Online diagramming application
Impact Client - The Impact client is an advanced utility mod for Minecraft, it is based on ClientAPI and includes a...
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.