4 Best Mattermost Alternatives for Windows in 2026

What is Rocket.Chat?

Rocket.Chat is an instant-messaging and team collaboration platform for enterprises and organizations that need private messaging, persistent chat rooms, direct messages, persistent user presence and file transfer capabilities. It does not require the installation of any client software, which ...

What is Zulip?

Zulip is enterprise software that makes it easy to set up a business IM network with dozens or thousands of people, while avoiding most of the problems of larger public IM systems such as scale, spam, usability and support. Zulip also has great features through which businesses can be more ...

What is Output Messenger?

Output Messenger is an easy to use software that allows business to connect with others and keep in touch, regardless of proximity. Output Messenger provides instant chat options, file sharing, a task manager and more. It also can work at no cost with business operations over the web, using ...

What is Trillian?

Trillian combines instant messaging and email into one integrated system that's a breeze to use. It lets user effortlessly combine IM and email contacts, and provides a multitude of ways to communicate with them regardless of their location, AIM or ICQ account, online status, or time zone. With ...