Slack - Slack is a cloud-based team collaboration tool. Slack no longer using an IRC backend, it offers a lot of IRC-like features like persistent chat rooms, organized by topic, as well as private groups and direct messaging. All content inside Slack is searchable, including files, conversations, and people. Slack integrates with a large number of third-party services and supports community-built integrations. Major integrations include services such as Google Drive, Trello, Dropbox, Box, Heroku, Crashlytics, GitHub, Runscope and Zendesk.
Bitrix24 - Bitrix24 is easily the best alternative to Slack for team communications. While the web is boasting of how Slack is revolutionizing internal communications, but Bitrix24 simply offers better features and pricing plans that would catch the attention of small teams and startups. Solo and group video calls, a file-sharing feature that syncs files across all your devices and getting notified when some edits are made, Shared calenders, tasks and to-dos forming the basics of project management; and also the facility for a self-hosted version makes Bitrix24 easily one of the best Slack alternatives.
HipChat - If pricing is an issue for your small business or startup to avail of these great team communications applications, HipChat is your best bet. With their highly competitive pricing and plans, you will get the best value for your money with HipChat. HipChat has been in existence 3 years prior to Slack and is widely in use by many individuals and businesses alike who love complete control over their team communications app.
Google Hangout - Google Hangouts is a communication platform developed by Google which includes instant messaging, video chat, SMS and VOIP features. It replaces three messaging products that Google had implemented concurrently within its services, including Google Talk, Google+ Messenger, and Hangouts, a video chat system present within Google+. Hangout is best for team communication upto 9people. Even you can share your conversation in YouTube.
Google Spaces - Spaces is a proprietary cross-platform application for group discussions and messaging developed by Google. The app is intended as a content sharing platform where users can create a "space", invite their friends for discussion, and share videos, images, text, and other media. Google services such as the web browser Chrome, search engine Google Search, and video sharing platform YouTube are built into the app to allow users to source content from them.
eXo Platform - eXo Platform is an excellent Enterprise-ready open source social platform for team communications to build their network upon. eXo platform offers a top-notch team communications platform that is completely customizable as per the necessities of the enterprises. With an open source social networking platform, eXo platform provides the ultimate team communications solution for a major enterprise.
Yammer - Yammer is a great premium team communications solution that integrates all the key features of such an app and offers the reliability on top of it. Microsoft is now the parent company for this tool and that makes it even easier to integrate and collaborate easily with other Microsoft products. With a powerful context-based search feature and support for all major platforms, Yammer is a great team communications alternative to Slack.
Microsoft Lync - Formerly known as Microsoft Office Communicator, Microsoft Lync is an enterprise software solution for Instant messaging and chat clients. This software is entirely different from other Microsoft owned chat clients, in it being targeted toward corporate environments. With its announcement of integration with Skype Business to provide a streamlined flow of information and better collaboration, Microsoft Lync seamlessly integrates with all Microsoft products, providing a better team communications.
Skype - Skype has been one of the great tools that still many businesses make use of for their team communications. With the announcement of an upcoming Skype for Business in the April of 2015, Skype still has a lot to offer for Businesses and corporate environments to better their team communications and collaboration. With the major features on Skype aimed at the general audience, they still make up one great tool which could be utilized for team communications and collaboration.
Fuze - Fuze offers a great free and premium plans for corporates to provide them a unified internal team communications experience across desktop and mobile platforms. Their easy-to-use interface and powerful team collaboration and communication tools make up a great tool that couldn't be simply ignored. With HD video calls and video conferencing, Fuze also acts as a great meetings platform for corporate environments.
Glip - Trusted by many major Fortune 500 companies, Glip is another free and premium based team communications and collaboration tool for businesses to consider. You can do away with using tens of cloud-based apps and use only Glip for management of your tasks and to-dos, calenders, chats, files, notes and video calling all in a single place. Managing projects, working on the go, interacting with clients - Glip possesses all of the key features enough to say goodbye to Email for your team communications.