xcyrBGR - The Bulgarian Cyrillic keyboard layout manager for X11 

Easy toggle leyaut <English/Cyrillic-BDS/Cyrillic-PHOnetic> 
Mouse click to toggle encoding (Win-CP1251/KOI8).

Cyrillic fonts for X11 (koi8 and cp1251):
ftp://aladdin.cblink.net/pub/FreeBSD/X11/X_cyr_fonts_koi_cp1251.tar.gz 

Veselin Slavov - vess 
vess@btc.net