Impulse Press is a WordPress starter theme based on Twitter Bootstrap. The theme is responsive and includes different page templates, javascript validation of comment posts. This theme is ideal for theme developers that would like to have a good framework to start with. There is also a premium version which you can look at here: http://www.impulse-press.com. There is free support available at: https://www.impulse-themes.com/forums/forum/impulse-press/