Zoom - Equip your team with tools designed to collaborate, connect, and engage with teammates and customers, no matter where you’re located, all in one platform.
Stack Overflow - Community-based Q&A part of the Stack Exchange platform.
Skype - Stay in touch with your family and friends for free on Skype. Download Skype today to chat and call on desktop and mobile.
The Answer Bank - The Answer Bank is the UK’s leading question-and-answer site.
WebEx - Cisco WebEx Web Conferencing, Online Meetings, Desktop Sharing, Video Conferencing
Askalot - Askalot is a next generation CQA (Community Question and Answer) system.