What would the tech stack be for designing a data visualization website?

What would the tech stack be for designing a data visualization website like:

• http://flowingdata.com/
• http://ift.tt/q3kLhT

Every post on these sites accesses different data sources to build a D3JS visualization. How would the data be stored and accessed for different posts? Also, I am unable to figure out if they built the website using blogging platforms like Wordpress or did they design the website from scratch or did they use a static website generator?