# dpkg -l | grep ruby
ii libruby1.8 1.8.7.358-7.1+deb7u3 amd64 Libraries necessary to run Ruby 1.8
ii libruby1.9.1 1.9.3.194-8.1+deb7u5 amd64 Libraries necessary to run Ruby 1.9.1
ii libruby1.9.1-dbg 1.9.3.194-8.1+deb7u5 amd64 Debugging symbols for Ruby 1.9.1
ii libtcltk-ruby1.9.1 1.9.3.194-8.1+deb7u5 amd64 Tcl/Tk interface for Ruby 1.9.1
ii ruby-full 1:1.9.3 all Ruby full installation (default version)
ii ruby-passenger 3.0.13debian-1+deb7u2 amd64 Rails and Rack support for Apache2 and Nginx
ii ruby-rack 1.4.1-2.1+deb7u1 all Modular Ruby webserver interface
ii ruby1.8 1.8.7.358-7.1+deb7u3 amd64 Interpreter of object-oriented scripting language Ruby 1.8
ii ruby1.8-dev 1.8.7.358-7.1+deb7u3 amd64 Header files for compiling extension modules for the Ruby 1.8
ii ruby1.9.1 1.9.3.194-8.1+deb7u5 amd64 Interpreter of object-oriented scripting language Ruby
ii ruby1.9.1-dev 1.9.3.194-8.1+deb7u5 amd64 Header files for compiling extension modules for the Ruby 1.9.1
ii ruby1.9.1-examples 1.9.3.194-8.1+deb7u5 all Examples for Ruby 1.9
ii ruby1.9.1-full 1.9.3.194-8.1+deb7u5 all Ruby 1.9.1 full installation
ii rubygems 1.8.24-1 all package management framework for Ruby libraries/applications