Stack Overflow - Community-based Q&A part of the Stack Exchange platform.
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.
The Answer Bank - The Answer Bank is the UK’s leading question-and-answer site.
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Askalot - Askalot is a next generation CQA (Community Question and Answer) system.
WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.