gistfile1.rb

require 'rubygems'
require 'typhoeus'
require 'json'
require 'date'
require 'ostruct'

apikey = "0187fce21254fce68e5858518443c207"
version_url = "https://rubygems.org/api/v1/versions"
gem_url = "https://rubygems.org/api/v1/gems"

all_gems = `gem list -r`.split("\n").map{|gem| gem.split(" ").first}.map(&:strip)

all_gems.each do |gem|
  gem_data = JSON.parse(Typhoeus::Request.get("#{gem_url}/#{gem}.json", password: apikey).body)
  uses_mongoid = gem_data["dependencies"]["runtime"].find{ |dep| dep["name"] == "mongoid"}

  if uses_mongoid
    last_release = JSON.parse(Typhoeus::Request.get("#{version_url}/#{gem}.json", password: apikey).body).first
    maintained =  Date.parse(last_release["built_at"]) > Date.new(2011, 10, 13)

    if maintained
      popular = gem_data["downloads"].to_i >= 10_000

      if popular
        p "#{gem}: #{last_release["built_at"]}/#{gem_data["downloads"]}"
      end
    end
  end
end

result

"carrierwave-mongoid: 2012-04-08T00:00:00Z/27103" -> needs gridfs
"delayed_job_mongoid: 2011-12-30T00:00:00Z/34019" -> there is already a pull request
"locomotive_cms: 2012-04-02T00:00:00Z/12886"
"mongoid-tree: 2012-02-06T00:00:00Z/13114"
"mongoid_session_store: 2011-11-03T00:00:00Z/10773"
"mongoid_slug: 2012-03-15T00:00:00Z/31495"