The T2 bundle provides a variety of separate support functions for using
Cyrillic characters in LaTeX: the mathtext package, for using Cyrillic letters
'transparently' in formulae; the citehack package, for using Cyrillic (or
indeed any non-ascii) characters in citation keys; support for Cyrillic in
BibTeX; support for Cyrillic in Makeindex; and various items of font support.
