Peer-to-peer communication software with the capability to make and receive audio and video calls to other Skype clients (for free) and land lines for low cost.  Additionally it supports instant messaging, chat rooms, audio & video conferencing, file transfers, text (SMS) messaging and voicemail.

In the second week of August 2014 Microsoft finally disabled logins from old versions of Skype. In order to use the Windows version of Skype you have to run version 6.14 or higher.

Beginning March 1, 2016, users running older versions of Skype for Windows desktop (7.16 and below) will no longer be able to sign in. Please don't try to use old versions of Skype for testing past this date.

Submitted test data from old Skype versions will be dismissed.

Application Details:

Developer: Microsoft

Super Maintainers: About Maintainership

Link Wikipedia

For more details and user comments, view the versions of this application

VersionDescriptionLatest RatingLatest Wine version testedTest resultsComments
2.0.XInitial release with video support for Windows XP and higher users.Bronze0.9.14.140
2.5.XAdded features like Social Spaces, SMS, and larger conference calls.Garbage0.9.25.80
2.6.XAdds webpage related features, Skypecasts, and mood messages.Garbage0.9.21.10
3.0.XAdds public chat, website ph # links, mood message links.Garbage1.1.32120
3.2.XAdds auto-invites to skype with GMail, Hotmail, Yahoo! Mail. Video snapshots, PayPal support, account management interface.Garbage0.9.46.30
3.5.XSkype version 3.5Garbage0.9.51.20
3.6.XVersion File size 22 MB. Official release. Release date: February 5, 2008. File name: SkypeSetup.exeSilver1.1.1332
3.8.XSkype 3.8 seriesGarbage1.1.730
4.0.XSkype 4.0 introduced a completely overhauled UI.  Now by default all Skype conversations take place in the central window.  Turning Skype from an small accessory to an app that requires nearly full screen.Garbage1.1.2130
4.1.xThe Windows version of Skype 4.1 series client.Garbage1.1.4030
4.2.xThe Windows version of Skype 4.2 series client.Garbage1.1.4450
5.0.xVersion 5.0Platinum1.7.23180
5.1.xVersion 5.1Garbage1.450
5.2.xVersion 5.2Garbage1.3.1710
5.3.xVersion 5.3Garbage1.440
5.5.xVersion 5.5Bronze1.7.1863
5.6.xVersion 5.6Garbage1.3.3710
5.8.xVersion 5.8Garbage1.431
5.9.xVersion 5.9Garbage1.5.113
6.xWhat's new in Skype 6:Silver1.7.3364
7.xSkype 7.x for PC features a new revamped UI, better UI customization and touch support.Bronze2.12017
Native version available
There is a native Linux version of Skype available at the official Skype website.

Also you can use Skype for a web browser.