Ask HN: How to best expose public data in an intuitive interface?

Recently I found that my country's (Lithuania) parliament provides a way to get quite a bit of data in regards to questions being raised, voting results, business trips, etc. One problem is that the data is in XML format with an undocumented schema.

I am going to clean up and organize the data but was wondering whether someone could recommend any existing tools that can help make this data accessible to any half-savvy computer user?

The goal is to help citizens make better voting decisions in upcoming election. I hope that being able to see what particular politician voted for/against in the past, and other relevant data, will enable make more informed data-driven decision whom to vote for. Thus, what's probably needed is an intuitive user interface for inspecting all this data but I hope to avoid the pleasure of having to build such interface myself.