Thursday marks 10 years since the launch of Skype, the calling software that may rank as the most successful internet company to come out of Europe. One in three international voice calls is now made using Skype.
But the celebrations will be muted, even among those who made billions from the technology. Skype's Swedish founders, Niklas Zennström and Janus Friis, who ended up suing the company twice, have moved on. EBay, which bought the company for $3.1 billion, was never able to generate synergies with its online marketplace, although it made a handy financial profit.
And some observers and former employees say Skype's first decade is a tale of missed opportunities.
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"In some ways Skype is a victim of its own success," said Taavet Hinrikus, the company's first employee. "It stopped innovating. The last meaningful thing to be launched by Skype was video calling in 2005."
Skype aimed to put traditional telephone companies out of business by making all calls free, leading one analyst to liken it to "a giant meteor hurtling on a collision course toward earth".
The software launched on August 29 2003 from a Soviet-era university block in Tallinn, Estonia. Its slogan was "Free internet telephone that just works".
That soon became a double entendre when call quality turned out to be volatile, yet within a month it had been downloaded 500,000 times.
It continues to grow. Skype had "more than twice the volume growth achieved by all the phone companies in the world combined" last year, according to Telegeography, a research organisation. It has had a particular impact on international calls, traffic growth for which has slowed a lot since 2008.
Yet that success could have been much broader.
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In 2005, a year before Twitter emerged, Skype started allowing users to enter a mood message alongside their name, but it did not expand the feature.
Skype never dominated instant messaging on mobile, despite promising as early as 2007 that it would do "much more than voice". Instead a new crop of chat app start-ups, such as Viber and WhatsApp, have become the mobile messaging tool of choice, especially in Asia.