Variants includes encodings and things like whether the font is slanted.
At the same time the sections on installation and such have been rewritten or expanded. All of these are generated by the same script that generates the fonts, so they should match the supplied fonts. There are ETX and MTX files included for making T1-encoded fonts from. It follows that systems without the ability to use VFs will not be able to use T1 fonts. The Cyrillic alphabet is still very incomplete, and some of the glyph designs need revision.