Use the sliders below to change the constituents of the Universe and see how it affects the Cosmic Microwave Background. You can toggle the power spectrum using the middle of the three buttons in the top right.
This tool was created for a Planck exhibit at the Royal Society Summer Science Exhibition 2013. You can see details of how it was written on Stuart Lowe's blog. If you'd like to use it elsewhere, then you can embed it in your site, or download the source-code from the Github repository.