UMLGraph - UMLGraph is a professional automated drawing tool that allows the designers the declarative specification and drawing of UML class and sequence diagram.
Totango - Totango is a Customer Success Software Platform
Dia - Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.
Churnzero - ChurnZero is the Customer Success Platform built for growing SaaS and subscription businesses.
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.
Planhat - Customer success has changed. Meet the modern Customer Platform!