Mattermost provides high trust collaboration and messaging solutions through an open source, community-powered approach. Enjoy all the productivity benefits of workplace messaging across web, mobile and PC, with unlimited archiving, search and integrations within IT-controlled private environments in public clouds, including AWS and Azure, as well as on-premise in private clouds and virtual or physical servers.

Google Meet

Link direto para utilizarem o WhatsApp Web sem necessidade de instalação. Terá algumas restrições mas funciona bem para uso diário.