Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform
Traverse Monitoring - Traverse Monitoring is an IT Management software that provides businesses with a network monitoring solution which is capable of handling the tasks of monitoring private clouds, distributed network infestation and virtualized infrastructure.
The Product Folks - A volunteer-led community of product managers and makers
Kernel for Exchange Server Recovery - Kernel for Exchange Server Recovery is another IT Management and file recovery tool that can successfully restore and recover all the deleted items, attachment, task, and contacts etc.
Basecamp Personal - Manage all your small projects for free
ManageEngine RecoveryManager Plus - RecoveryManager Plus is one such enterprise backup solution which has the ability to easily backup and restores both the domain controllers and virtual machines.