What do you mean by 'opening software' ?
What do you expect from it ?
I think Fritz and Chessmaster both have a fairly simple feature that can teach you and let you practice lines in some openings.
There are 2 programs, Chess Openings Wizard (commcerical) and Chess Position Trainer (free) that are used for opening learning, but you have to enter the lines to be trained yourself, or find books that have already been created by others to use.
ChessOK has some software for teaching openings as well. The Opening Instructor, which is currently being ported to the newer Peshka interface, is one. They also have Encyclopedia of Opening Bllunders, and possibly some others.
Chessbase has some opening DVDs too.
Agreed on the Chessbase thing - those videos are absolutely stellar. You can play them in Chessbase Light too, so there isn't necessarily a need to purchase Fritz, although I have Fritz 10 with the Shredder 11 package, and will never look back. The program is simply superior for tournament/club players. Databases, opening books, video lectures, engines - all can be purchased for the Fritz program.
And, with most the avalable engines either approaching or surpassing the 3,000 ELO level, you cannot go wrong. Even the "weak" engines play way above master level chess.
Try the opening explorer on Chessgames.com and some clips on ICC, real people talking is the best "software"
what is the best opening software i heard chessmaster and fritz has an opening thing. what's the best opening software?
EDIT: Software to learn openings and study openings and to help memorize and maybe also an opening database.