Based on our record, Tigase seems to be more popular. It has been mentiond 1 time since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
"Best" is relative but to add to other voices maybe try also looking at Tigase XMPP Server (https://tigase.net/, https://github.com/tigase/tigase-server)? Source: over 2 years ago
Prosody - Prosody is a modern flexible communications server for Jabber/XMPP written in Lua.
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.
Openfire - Openfire (formerly Wildfire) is a cross-platform instant messaging (IM) and groupchat server.
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Matrix.org - Matrix is an open standard for decentralized persistent communication over IP.
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.