LinuxCNC (the Enhanced Machine Control) - LinuxCNC: an open source CNC machine controller. It can drive milling machines, lathes, 3d printers, laser cutters, plasma cutters, robot arms, hexapods, and more.
Freshservice - Freshservice: the one-stop cloud solution for all your IT management needs.
PyCAM - PyCAM is a toolpath generator for 3-axis CNC machining.
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
Mach3 - Mach3 is very popular among the Hobby CNC community.
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.