Most of contemporary operating systems are easy to personalize in terms of additional languages and keyboard layouts. Instructions for that are freely available on their manufacturers' websites. See, for example, multi-language computing manuals for Windows 7, 8 and Mac OS X:
URL: Windows 7: Install a display language
URL: Windows 8: Change your language or keyboard
URL: Mac OS X: Displaying different languages
If your computer runs earlier versions of Windows or Mac OS or you would like to get more information on the topic of the Cyrillic computing in its historical context, we recommend you to take a look at these two websites. They have an abundance of information on every aspect of this problem: fonts, keyboard layouts, encodings, Unicode-related issues, etc. For Macintosh make sure to browse the third (previous) version of the Russification for Macintosh website.
One of the problems that can occur when you work with a text in a foreign language is a number of special characters and diacritical marks that you cannot find on a regular English language keyboard. While this problem is usually solved by installing (and learning) a new language keyboard layout, very often the need for additional characters can be met by using a standard English keyboard layout and a few additional features. Typing international accent marks website provides a number of Alt key codes and shortcuts for typing special characters and diacritics (acute and grave stress, circumflex, cedilla, etc.) It covers several operating systems, text editing programs, and devices like BlackBerry and iPhone/iPod.
The American Association of Teachers of Slavic and East European Languages compiled a webpage with instructions on preparing your computer for multilanguage use. Additionally, they provide a number of Medieval Slavic Fonts that are not included in standard operating systems releases.
Oftentimes a problem of typing a text can be temporarily solved by using an online keyboard. Typeit.org offers a number of virtual keyboards including those for East-European languages: Czech, Hungarian, Polish, Romanian, and Russian. Additionally, there are a number of specialized websites that offer rare and unique virtual keyboards, for example, an Old Church Slavonic keyboard at www.churchslavonic.org.
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