Serbian language can be equally written using cyrillic or latin alphabet. It used to be strictly phonetic, according to the "write as you speak, read as it is written" rule, set by Vuk Karadžić back in mid-XIX century.
What with globalization and recolonization of the ex-socialist countries, everything is getting anglified, and most of the global corporations don't bother to hire translators, so there's a lot of English in the official newspeak. Big corporations like Microsoft and Google don't want their names to be written phonetically (as Majkrosoft, Gugl), and insist on English spelling even inside the cyrillic versions of their texts - just visit their pages on any cyrillic country's branch of their websites.
Official alphabet of the government at all levels is cyrillic; there is usually a latin version of pretty much everything of importance. Road signs are in both scripts, plus minority languages where needed. However, don't bother looking for cyrillic labels on anything you buy. Some small shops may use cyrillic for local colour or that domestic feel, but anything made in a factory will most probably be in latin script (or in English, for that matter).
There's also the new illiteracy afoot, where the cyrillic is completely gone, and the latin is written using only the 26 English characters - by losing the diacriticals from š, đ, č, ć and ž. This introduces some nice ambiguity; the list of confusing cases is here (in Serbian only, it would be too much to translate it all).
The above paragraph would look like this if such rules were applied to english:
Tere's also the new illiteracy afoot, were te cyrillic is completely gone, and te latin is written usin only the 26 Englis caracters - by losing the diacriticals from š, đ, č, ć and ž. Tis introduces some nice ambigity; the list of confusin cases is here (in Serbian only, it would be too muc to translate it all).
The name for this kind of language is, unofficially, engrbian (engrpski), by analogy with franglais, germisch and others.