The Cyrillic alphabet and the languages that use it.
About the alphabet itselfCyrillic alphabet comes from the time of the Christianization of Kievan Rus. As legend says, it was created by two monks, Cyril and Methodius, to be used as the Slavic peoples' alphabet. In truth, they created the Glagolitic alphabet, which is the early version and looks very different from the known Cyrillic. The original Cyrillic was actually created by their Bulgarian disciple Saint Clement of Ohrid (Kliment Ohridski), who simplified it by making the script more similar to Latin and named it after his teacher Cyril. This original alphabet survives today as the alphabet of ceremonial books in the Russian Orthodox Church. However, the Slavic languages have changed significantly, and today we have several simplified Cyrillic alphabets, each tied to a specific language. The major difference of Cyrillic from Latin script is that some Cyrillic letters change the way the previous letter is pronounced (which is actually quite common in various scripts using Latin too, but as they are much more varied, hardly anyone notices), but all changes are somehow systematic — unlike, say, as it it in English.note . There are a few exceptions from pronouncing rules, but even they may still be pronounced as written without misunderstanding. The major inherited problem with Cyrillic scripts is that it shares very few letters with Latin scripts, or, more precisely, in many cases it uses the same glyphs to denote different sounds: for example, Cyrillic letter "Р/р" corresponds not to the Latin "P/p", but "R/r". Thus, it requires its own 66 or more codepoints in character encoding. In the past, when single-byte encodings were used, there were at least three incompatible character encodings for Russian Cyrillic in active use and some for other languages as well. Even now, 'translit', i.e. direct transliteration of Cyrillic letters with some groups of Latin letters, is in active use when normal Cyrillic is hard to use. Another historical note is that Cyrillic appears to not be the first Slavic writing system. Before it and Glagolitic alphabet, early pagan Slavs apparently used their own indigenous writing system, known as "cherty i rezy", "strokes and incisions", after the offhand mention in a book by the Bulgarian monk and writer Hrabr. Unfortunately, so little remained from the pre-Christian Slavic culture that now there are no undoubted specimens of that writing, which some linguists presume to be runic in nature and used mostly in pagan religious rituals, while others speculate that it was much more widespread and used as a common writing, being syllabicnote and close in nature to the early Greek "linear scripts" or Japanese kana. See also The Backwards R, which often employs Latin letters to represent Cyrillic ones in order to create a mock-Slavic writing style. (Nothing to do with an international chain of toy megastores.)
Languages that use Cyrillic
BelorussianA fun thing: despite the name, in most of the Belarus, Russian is the native language. Most people speak it both at home and in official settings, Belorussian being now mostly associated with poor farmers and the like, despite the government stating that both languages are official. In fact, up until the beginning of the 20th century Belorussian wasn't considered a language on its own at all, but was seen as a particularly rustic (and Polonized) dialect of Russian. One of the constant points of ridicule about Belorussian president Alexander Lukashenko is that being a country bumpkin he speaks neither Russian, nor Belorussian, but rather a common pidgin known as trasyanka, which is widespread in the rural areas. Since the beginning of the 20th century Belorussian nationalists try to reinvent it as an elite language, but given that their chief activity seems to be more squabbling with each other, the result is nowhere in sight, and their involvement actually seems to make the situation worse: now there are two separate literary dialects, and three writing systems, two using Cyrillic and third Latin.
BulgarianBulgaria was a member of the Warsaw Pact during the Cold War, but is now a member of NATO and The European Union (as are the rest of the "buffer states"). It was also the country where the Cyrillic alphabet was created and first taught and used. It is also somewhat mutually intelligible with Russian and uses a pretty similar subset of wider Cyrillic.
MoldovanRomanian with a new (or archaic, depending on who you ask: Moldovan (which is mostly treated as a dialect of Romanian) originally used Cyrillic, being the only Romance language to do so, and switched to Latin script only relatively recently, in the Late Middle Ages, when Moldovan/Romanian principalities started to gravitate closer to Hungary, out of their usual South Slavic sphere) orthography imposed to justify a Soviet landgrab in The Thirties. Post-Soviet Moldova uses the Latin alphabet, but it has one minor orthographic difference with standard Romanian across the border. Cyrillic Moldovan is still used in the breakaway province of Transnistria, though, as it is generally Russia-aligned.
RussianThere is not just one Russian accent (dialects would be the better word), but two or three:
SerbianThe language of the country that is the successor state to the former Yugoslavia and which appears to be about to lose yet more territory to the new Kosovo/Kosova. The language was formerly collected together with Croatian and Bosnian (which use the Latin alphabet) as Serbo-Croat, but they are now separated by linguists — though, as it was noted many times, a language is a dialect with an Army and a Navy, so their separation is seen by many as mostly a political move. All three language remain mutually intelligible anyway. It has a few extra characters, such as "J". Due to the fact that Serbians played a major part in the horrors of the Balkans Wars, Serbia is a common place from which to source villains and therefore the language comes with it. One of the more notable instances of the use of the Serbian language in fiction is the revelation of Nina Myers as The Mole in 24. Nina uses Serbian (to delay the revelation a few seconds longer) in her conversation with Victor Drazen (the Serbian spelling is Viktor). The on-screen subtitles have her stating "It's Yelena", her Code Name. Serbians would spell it "Jelena", as in the tennis player Jelena Janković. The writers probably didn't want the American audience thinking it sounded like "Gel-an-ah". Speaking of Viktor Drazen and his family, their names are a case of artistic license since Drazen is a first name, not a family name; his wife Elena should be Jelena; Andre should be Andrej and Alexis should be Aleksej, and those two names would even so only be used if the parents were huge fans of Russian literature.
UkrainianUkrainian is very similar to Russian and people from the different countries can have conversation, but there are differences, sometimes even in basic words. Ukrainian itself has dialects. The eastern one is more like Russian, and in border regions of Russia and Ukraine a mix of Russian and Ukrainian known as surjik is in active use. Not everyone in Ukraine speaks Ukrainian at home, although nearly everyone knows it. The rough division is a line running through Kyiv/Kiev and very closely matches the voting patterns in the 2004 Presidential Election (with Ukrainian users tending to vote for Yushchenko and Russian users for Yanukovych).
MongolianMongolia's official writing system for the Mongolian language has been Cyrillic script since the 1940s. (http://en.wikipedia.org/wiki/Mongolian_writing_systems#Cyrillic_script). Note that the Mongolian language is written in more traditional scripts in other places, such as the Inner Mongolia region of China. In Mongolia itself, the traditional alphabet is being reintroduced mainly for national pride.
OthersIn addition to these, there are several languages in Russia and the rest of the former Soviet Union that wound up with a Cyrillic orthography because they did not have an alphabet (much like almost all Native American languages have a Latin orthography). Several other nationalities in Russia and the former Soviet Republics (Azeris, Kazakhs, Tajiks, Turkmens, Tatars, Chechens, etc.) had preexisting (usually Perso-Arabic) orthographies replaces with Cyrillic ones during the Soviet era, although most of them outside Russia are phasing them out. Please note that Czech, Slovak, Polish, Lithuanian, and a lot of other Slavic and other Eastern European languages do not use Cyrillic alphabet, and sometimes even assuming that they can read it could be offensive.
Andrey or Andrei- Transliteration IssuesBecause not all the letters directly translate into English sounds, you get various approaches to Cyrillic-Latin transliteration. This is why you get the Project 955 missile submarines either spelt "Borey" or "Borei" in English. There are a number of different systems, such as that used by the Library of Congress. You will sometimes get the words, in either alphabet given those little line accents called "udareniye". These aren't actually used in writing, they're just pronunciation aids.