Hyphen Messaging is a powerful network and administration application that enables users to communicate securely with colleagues, customers, and partners across multiple platforms. It provides a secure, reliable, and robust messaging solution with both private and public channels. With Hyphen Messaging, users can easily create, manage, and share messages, files, documents, and other content in a secure and convenient manner. The application also provides users with insights into who is participating in their conversations, as well as their activity. Hyphen Messaging also provides a comprehensive set of administrative features to manage user access, permissions, and security. This allows administrators to control who can access and use the messaging application, as well as set up customized access and permission levels for each user. Hyphen Messaging is a highly secure and reliable messaging application that allows users to communicate securely with colleagues, customers, and partners.
Discontinued As stated on https://github.com/sdelements/lets-chat/issues/781, the project is no longer in development as of August 2017. The latest version, 0.4.0, released in June 2015, can still be downloaded from GitHub along with the source code.
Skype
Slack
Mattermost
Matrix.org
Rocket.Chat
Glip
HipChat
Gitter
fluxday
Let's Chat
YakYak
Hack Chat
ZeroChat
Flock
Dialog Messenger
Ripcord
Spectrum Chat
MongooseIM platform
Plus Messenger
Campfire
Discontinued https://alternativeapp.info/software/slack/ is acquiring Hipchat and https://alternativeapp.info/software/stride-by-atlassian/ from Atlassian. services will be discontinued after February 15, 2019. https://www.atlassian.com/partnerships/slack