info-apropos.el provides an
M-x info-apropos for Emacs, the same as
M-x index-apropos in the stand-alone info reader.
M-x info-apropos searches for a string in the indexes of all info documents installed on the system. This is good for finding references to something when you’re not sure what documents might be relevant.
The Emacs cvs head (which will be Emacs 22 or whatever) has adopted this feature, so
info-apropos.el is only needed for Emacs 21.
Get it from the author JesperHarder at