Blog Du Webdesign invites you to discover a very interesting resource for integrators and web designers as well as developers: HTML5 up website
HML5 Up is a website that, for now, brings together 19 HTML5 templates that are responsive, integrated and free of copyright to be used as inspiration or working base.
Portfolio, blog, presentation page… You will find anything you need.
A very convenient module allows you to browse each template and makes it possible to re-size the view in iPad or iPhone layout, which makes the responsive test easier.
But be careful: those are only HTML5 templates, not CMS themes. You will still need to make them dynamic by integrating the CMS you want.