Chat and talk
Google Chat is the same simple but powerful tool available to the public; users can see presence for Google Apps contacts inside Gmail and start a text, voice or video chat from there once they've downloaded the plug-in. Alternatively they can use the Windows Google Talk software for text and voice chat or file transfer. Management is minimal; you can block chat outside the organisation or just warn users but you can't block file transfers.
Microsoft's Lync Online is more powerful. The extensive management options let you choose whether users can transfer files, make audio or video calls and talk to people outside the business or just colleagues.
Users can see each other's presence and status in Outlook and Outlook Web Access (including information from someone's Exchange calendar), and in any Office app where you're collaborating. It's possible to start a chat, voice or video call from there or from the Lync client. Microsoft is also promising Lync clients from a range of smartphones, offering IM first and voice features later. If you have an in-house PBX you can also set up unified messaging (like dialling phone calls from Outlook) and integrate voicemail with Exchange Online although we weren't able to test this.
Lync Online automatically federates with Windows Messenger and AOL for instant messaging.
Lync Online automatically federates with Windows Messenger and AOL for instant messaging. It can also federate with on-premise Lync servers if permitted by the server admin.
Google Apps can federate with any XMPP service, but to make that work you have to edit the SRV record in your domain by hand (or ask your domain hoster to do it for you), and you then get federation with all the services Google is connected to - you don't get to choose which are allowed or blocked. Similarly, you can allow users to chat with any Gmail or Google Apps user or block them all; you can't pick and choose which Google Apps-using companies they can communicate with and you can't block or allow chat access for specific users (individually or by groups).
Lync Online also incorporates the features of LiveMeeting; you can switch from an IM chat to an online meeting with up to 250 people with audio, video and Web conferencing, and you can schedule meetings in advance through Outlook. If you want to let people phone in to a meeting without needing Lync (customers for example), you can buy an audio conferencing service for Lync Online from BT.
Winner: Office 365. Google App's chat and messaging features are fine for most users, but for more fine-grained controls, Office 365 is better.
