Lotus Sametime vs Microsoft Lync

Lotus Sametime
IBM Sametime is a client–server application and middleware platform that provides real-time, unified communications and collaboration for enterprises. Those capabilities include presence information, enterprise instant messaging, web conferencing, community collaboration, and telephony capabilities and integration.
Microsoft Lync
Microsoft Lync (formerly Microsoft Office Communicator) and Microsoft Lync for Mac are instant messaging clients used with Microsoft Lync Server or Lync Online available with Microsoft Office 365. Basic features include instant messaging, Voice Over IP and Video Conferencing inside the client software.
Face to face in the news:

1999 - Lotus ships enterprise messenger Lotus Sametime - a new advantage over Microsoft Lync

Today, IBM unveiled Lotus Sametime, the solution designed for instant messaging and collaboration over the Internet. The solution is built on Ubique aquired by IBM and consists of Sametime Connect Client and Sametime Server. The Lotus Sametime functionality includes a online status monitoring, instant messaging and object sharing, which allows to simultaneously work with documents and applications over the Internet like in Microsoft NetMeeting. The server costs $ 5,000 and client license costs $20 per user. Lotus Sametime is available as a standalone product or as a component of Lotus Notes / Domino.