wercker vs. Drone.io

Wercker integrates with your favorite developer platforms out there, such as GitHub and Bitbucket. When you are ready to deploy your application, wercker enables you to deliver your application to cloud platforms like Heroku, OpenShift and Amazon Web Services.

Drone is a hosted continuous integration service. It enables you to conveniently set up projects to automatically build, test, and deploy as you make changes to your code. Drone integrates seamlessly with Github, Bitbucket and Google Code as well as third party services such as Heroku, Dotcloud, Google AppEngine and more.