These scripts create unicode (UTF-8) index for the Cyrillic alphabet in the TeX system. This is by means of makeindex, sed and iconv. These scripts extend rumkidx.
The program makeindex (from a standard TeX system) does not understand unicode, only ANSI - and in case of Cyrillic letters - that is CP1251.
The archive contains sed and iconv for Windows. Extract the archive, double-click cyridx.bat to convert all *.idx files in the directory.
For Linux, which usually has sed and iconv, the script is self contained (does not depend on the rest of the files): cyridx.sh file.idx
For more information, see README_EN.TXT in the archive.
Download the cyridx scripts (version 3).