Tempra is a project mainly written in ..., it's free.
Template for rails 3
sqlite
rails new app_name -JT -m http://github.com/mauriciodeamorim/tempra/raw/master/setup.rb
mysql
rails new app_name -JT -d mysql -m http://github.com/mauriciodeamorim/tempra/raw/master/setup.rb
Test #{app_name} apply "#{tdir}/test.rb"