Ruby-vagrantboxes is a project mainly written in Ruby, it's free.
Ruby gem for interacting with the vagrantbox.es api from inside vagrant
This application extends the vagrant command line tool to allow for searching the vagrantbox.es repository of base boxes.
vagrant vagrantboxes search
vagrant vagrantboxes search centos
vagrant vagrantboxes search "debian puppet"
vagrant vagrantboxes show 1
vagrant vagrantboxes url 1
vagrant vagrantboxes add 1
Here's a simple example of the output:
vagrant vagrantboxes search centos 3 centos 5.5 http://dl.dropbox.com/u/15307300/vagrant-0.7-centos-64-base.box 6 opscode centos 5 http://opscode-vagrant-boxes.s3.amazonaws.com/centos5-gems.box 7 opscode ubuntu 10.04 http://opscode-vagrant-boxes.s3.amazonaws.com/ubuntu10.04-gems.box 9 puppet centos 5.5 64 http://puppetlabs.s3.amazonaws.com/pub/centos5_64.box 10 puppet centos 4 64 http://puppetlabs.s3.amazonaws.com/pub/centos4_64.box 21 centos 5.6 32 http://yum.mnxsolutions.com/vagrant/centos_56_32.box
The easiest way of installing is to use the gem.
gem install vagrantboxes