The software Skype was created in 2003 by two entrepreneurs from Sweden and Denmark, Niklas Zennström and Janus Friis, and by a team of software developers, Ahti Heinla, Priit Kasesalu and Jaan Tallinn based in Tallinn, Estonia [2
]. It allows users to make phone calls over the Internet to other computers with the Skype software, or even to conventional telephones and cell phones, these for a fee that is usually lower than the ones normally used. The software also allows the user to transfer files and send instant written messages. Videoconferencing was introduced in 2006 for the Windows and Mac OS X platform clients and in 2007 for Linux version 2.0. The first version used for videoconferencing, 18.104.22.168, supports "High Quality Video" with quality and features (full-screen and screen-in-screen modes) claimed to be similar to middle-range video-conferencing systems. Versions for Microsoft Windows 2000, XP, Vista and Windows Mobile, Mac OS X (Intel and PPC) and Linux (32-bit ×86 only) are now available. Skype can be run from a USB stick without being installed on the target computer in the Windows system. Skype is reportedly willing to accept thousands of connections, but is stated to limit itself to 40 Kb/s upload and download. The communication is considered secure and encryption cannot be disabled without the user seeing. One has to remember that Skype provides an uncontrolled registration system for users with absolutely no proof of identity, so the displayed caller's name is no guarantee of authenticity [3
The concept for messenger (Windows Live Messenger, MSN) was created by the Advanced Technology Group at Microsoft, headed by Nathan Myhrvold. MSN was originally a dial-up online content provider. Service was initially included with Windows 95 installations for simple written conversation as a chat. Nowadays, the new version allows the user to transfer files, share many folders with a specified user, have on line conversations, play games, and remotely access another computer [4
The programs MSN and Skype can be used for discussion of cases, second opinion, or even, in the case of Skype, for a video conference (chat) with the participation of some specialists in the most varied localization. In both systems you can create a conference with many users. These functions are very important when you need to participate in a meeting and you can't be physically in the place, or if you need, as in the case of pathologists, a second opinion on a case and you don't have enough time. A good example is frozen sections that some authors have described being done through this method. One person does the frozen sections, slides and the transmission and the pathologist, in any place, can see the images and give a diagnosis.