In September 2009

Skype

Skype (/skaɪp/) is a proprietary telecommunications application that specializes in providing video chat and voice calls between computers, tablets, mobile devices, the Xbox One console, and smartwatches over the Internet. Skype also provides instant messaging services. Users may transmit text, video, audio and images. Skype allows video conference calls.

At the end of 2010, there were over 660 million worldwide users, with over 300 million estimated active each month as of August 2015.^[6] At one point in February 2012, there were 34 million users concurrently online on Skype.^[7]

In March 2020, Skype was used by 100 million people on a monthly basis and by 40 million people on a daily basis,^[8] which was a 70% increase in the number of daily users from the previous month, due to the COVID-19 pandemic.^[9]

First released in August 2003, Skype was created by the Swede Niklas Zennström and the Dane Janus Friis, in cooperation with Ahti Heinla, Priit Kasesalu, Jaan Tallinn, and Toivo Annus, Estonians who developed the peer-to-peer backend that was also used in the music-sharing application Kazaa. In September 2005, eBay acquired Skype for $2.6 billion.^[10] In September 2009,^[11] Silver Lake, Andreessen Horowitz, and the Canada Pension Plan Investment Board announced the acquisition of 65% of Skype for $1.9 billion from eBay, which attributed to the enterprise a market value of $2.92 billion. Microsoftbought Skype in May 2011 for $8.5 billion. Skype's division headquarters are in Luxembourg, but most of the development team and 44% of all the division's employees are still situated in Tallinn and Tartu, Estonia.^[12][13][14]

Twitter

Twitter is an American microblogging and social networking service on which users post and interact with messages known as "tweets". Registered userscan post, like and retweet tweets, but unregistered users can only read them. Users access Twitter through its website interface or its mobile-device application software ("app"), though the service could also be accessed via SMS before April 2020.^[13] Twitter, Inc. is based in San Francisco, California, and has more than 25 offices around the world.^[14] Tweets were originally restricted to 140 characters, but was doubled to 280 for non-CJK languagesin November 2017.^[15] Audio and video tweets remain limited to 140 seconds for most accounts.

Twitter was created by Jack Dorsey, Noah Glass, Biz Stone, and Evan Williams in March 2006 and launched in July of that year. By 2012, more than 100 million users posted 340 million tweets a day,^[16] and the service handled an average of 1.6 billion search queries per day.^[17][18][19] In 2013, it was one of the ten most-visited websites and has been described as "the SMS of the Internet".^[20] As of 2018, Twitter had more than 321 million monthly active users.^[10] Twitter is a some-to-many microblogging service, given that the vast majority of tweets are written by a small minority of users.^[21][22]