gem guide
http://docs.rubygems.org/read/book/2
1 gem outdated # give list of gems which are outdate 2 3 gem list # list of all gems in the system with thier version number.if there was 2 version then it would give them in descending order 4 5 gem cleanup # clean the older version when there are 2 version available 6 7 gem dependency rails # list all the dependencies for a gem 8 9 gem install rails –no-rdoc # skips documentation 10 11 gem server # run in localhost:8808 rdoc documentation 12 13 gem query --remote --name-matches rails # find a gem 14 15 gem sources # list repositories