Windows Messenger 5.0 ( Live Communications Server 2003).Skype for Business Server 2019 is supported through October 14, 2025. Since September 2019, Skype for Business Online is no longer offered to new Office 365 subscribers, and are being directed to Microsoft Teams instead. Microsoft released a final on-premises version of Skype for Business Server as part of Office 2019 in late 2018, and announced in July 2019 that the hosted Skype for Business Online will cease functioning on July 31, 2021. On September 25, 2017, Microsoft announced that Skype for Business would be discontinued in the future in favor of Microsoft Teams, a cloud-based collaboration platform for corporate groups (comparable to Slack) integrating persistent messaging, video conferencing, file storage, and application integration. On October 27, 2016, the Skype for Business for Mac client was released. On September 22, 2015, Skype for Business 2016 was released alongside Office 2016. On November 11, 2014, Microsoft announced that Lync would be renamed Skype for Business in 2015, also adding support for video calls with Skype users. This initially included support for text and voice communications.

In May 2013, Microsoft announced that it would allow Lync users to communicate with Skype, a consumer IM platform it had acquired in 2011. In November 2010, the platform was renamed Lync. Microsoft released the successor to Office Communicator, Lync 2010, on January 25, 2011. It was followed by Office Communicator 2007 R2, released on March 19, 2009. Microsoft released Office Communicator 2007 to production on Jand launched it on October 27, 2007. Support for Skype for Business Online ended in July 2021, and Skype for Business Server 2019 will receive extended support through October 14, 2025. In September 2017, Microsoft announced that it would phase out Skype for Business in favor of Microsoft Teams, a new cloud-based collaboration platform. In 2015, the software was rebranded from Lync to Skype for Business, co-branding it with the Microsoft-owned consumer messaging platform Skype (which had begun to integrate with Lync in 2013). It supports text, audio, and video chat, and integrates with Microsoft Office components such as Exchange and SharePoint.

It is designed for use with the on-premises Skype for Business Server software, and a software as a service version offered as part of Office 365. Skype for Business (formerly Microsoft Lync and Office Communicator) was an enterprise software application for instant messaging and videotelephony developed by Microsoft as part of the Microsoft Office suite.

Skype for business user guide 2017