The new Office 365 Business and Business Premium plans released in October do not include the full Lync client so what are users expected to use for instant messaging, presence and online meetings?
There are a number of possible Lync clients including the Lync Windows Store App (Modern UI), Lync Web App and mobile Lync clients for Windows Phone, iPhone, iPad and Android devices. The most likely alternative for users will be Lync Basic which is a no-cost application to connect to Lync Online or Lync Server. For users already on Office 365 Small Business Premium or Midsize Business plans who are upgrading to the new Business plans, the update process will uninstall the Access & Lync applications and users will be able to download Lync Basic from their software portal in Office 365.
Although the functionality of Lync Basic was recently updated to more closely match that of the full Office Lync client, there are some quite significant differences including the lack of spellchecker for instant messages (after a long time of asking Microsoft to add a spell checker to Lync, losing it now is disappointing), using OneNote for Lync meeting notes and the ability to record meetings. Some features are not so relevant for SMB customers and there are also features which require on-premises Lync Server or SharePoint Server such as Skill Search and Persistent Chat; those features would not be available to Office 365 users even with the full Lync client.
If you’d like to understand the differences between Lync, Lync Basic and the other clients, you can view this TechNet page. There’s also a dedicated page comparing functionality for the Lync mobile clients.