Extended maintenance of Ruby versions 1.8.7 and 1.9.2 ended on July 31, 2014. Read more
Encapsulate all the strangeness to do with finding out where to find RDoc files
We basically deal with three directories:
The 'system' documentation directory, which holds the documentation distributed with Ruby, and which is managed by the Ruby install process
The 'site' directory, which contains site-wide documentation added locally.
The 'user' documentation directory, stored under the user's own home directory.
There's contention about all this, but for now:
$datadir/ri/<ver>/system/…
$datadir/ri/<ver>/site/…
~/.rdoc