Microsoft is closing down Skype, the video-calling service it bought for $8.5 billion in 2011, which redefined how people communicated online.
The tech giant said it would retire Skype in May and shift some of its services to focus on its flagship video-conferencing platform Teams.
To ease the transition from the platform, Skype users will be able to use their existing accounts to log into Teams.
Microsoft declined to share the latest user figures for Skype and said there would be no job cuts due to the move.
When Microsoft bought Skype in 2011, the service had about 150 million monthly users. By 2020, that number had fallen to roughly 23 million, despite a brief resurgence during the pandemic.
It added that Teams had about 320 million monthly active users.
Microsoft said on Friday "Skype has been an integral part of shaping modern communications".
"We are honoured to have been part of the journey."
Following news of its imminent closure, Skype users past and present described their memories of using the service for video calls and the impact it had on their lives.
"My best friend and I share many good memories on Skype," one X user said. "This is a sad day and almost a feeling of losing yet another fragment of my adolescence."
"While I knew the day would come, it's still sad. A lot of good memories there in an era when it was needed the most," another user wrote.
Skype will ring for the last time on May 5.
Skype struggled to keep up in smartphone era
Founded in 2003 by a group of engineers in Estonia, Skype was a pioneer in making telephone calls using the internet instead of a landline.
The company became a household name and boasted hundreds of millions of users at its peak.
"You no longer had to be a senior manager in a Fortune 500 company to have a good-quality video call with someone else," said Barbara Larson, a management professor at Northeastern University.
"It brought a lot of people around the world closer."
But the platform has struggled to keep up with easier-to-use and more reliable rivals such as Teams, Zoom, WhatsApp and Salesforce's Slack in recent years.
The decline is partly because Skype's underlying technology is not suited for the smartphone era.
When the COVID-19 pandemic and work-from-home measures fuelled the need for online business calls, Microsoft batted for Teams by aggressively integrating it with other Office apps to tap corporate users — once a major base for Skype.
James Hennessy, ideas editor at Capital Brief and host of the tech podcast Down Round, said Skype's downward decline had "been a bit of a slow-motion car crash".
"Since the mid-2000s, it's gone through a real loss of its strategic lead," Hennessy told ABC Weekend Breakfast.
"Microsoft didn't know exactly how to make Skype work within their suite of products.
"The real testing ground for it was during the pandemic. By the time that happened, Skype had become so complicated to use and that's where Zoom slid in."
Service traded hands repeatedly
The service traded hands many times during its 21-year run.
Ebay bought Skype in 2005 for $2.6 billion and later added video calls.
A group of private equity investors took control of the platform in 2009, then sold it to Microsoft in 2011 for $8.5 billion in what was then the computing giant's biggest acquisition.
By then, Skype's services were used so widely that its name became a verb, akin to Google or Uber.
"The Skype brand has become a verb, nearly synonymous with video and voice communications," then-Microsoft CEO Steve Ballmer said at the time.
ABC/AP/Reuters