Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
Microsoft 365 - Boost your productivity with reliable access anywhere with services like email, calendar, file sharing, meetings, instant messaging, and Office Online
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
Apache OpenOffice - Apache OpenOffice is an open source, office document productivity suite.
HelpScout - Help Scout is a simple, straightforward way to provide excellent support
SoftMaker Office - SoftMaker Office is one of the most powerful and reliable office suite that is fully compatible with the MS Office Suite.