I proudly joined the team working on the italian official open data portal dati.gov.it.
The website is important beacause offers metadata on the majority of open datasets published from the government at different administrative levels (national, regional, provincial and municipal), on different topics (health, education, business, etc.).
The work was commisioned to InsideOut10 and I helped by building a treemap allowing visitors to browse the available datasets directly in the home page. We also had fun coding a PHP script to organize the data visualized from the treemap in different ways. Starting from a flat dataset, the script can rearrange the data in a tree with an arbitrary hierarchy of the records’ variables (for example organization -> territory -> topic or territory -> topic -> organization).
Here is a working demo of the treemap:
The best news is that the treemap is open source and built to be easily reused with your data. You can find the treemap and a tutorial on github.