Another option is to build an index of the various parts of $LOAD_PATH. I monkeypatched (JRuby) to do this at runtime (that is, re-index every launch), and I s

Another option is to build an index of the various parts of $LOAD_PATH. I monkeypatched (JRuby) to do this at runtime (that is, re-index every launch), and I saw a modest speed up in Rails boot time. If there were a standard way to build a semi-permanent index (updated by 'gem install', etc.), I'd expect the index to give even further gains. Of course, this is more invasive than your suggestions. https://gist.github.com/pmahoney/3996724 https://gist.github.com/pmahoney/3996724