How would you go about coding an interactive website to display stats/graphs. Say I wanted to create something interactive for people to look at Stackoverflow stats - something that looks like awstats / google analytics but allows you to drill down to stats/graphs like:

• All questions: total, by hour of day, by day of week (interesting timezone challenge there, or just stick to UTC).
• Tags (e.g C# questions, app-engine questions): totals, by hour of day, by day of week
• Select a user: totals, by hour of day, by day of week
• Extra cool: the ability to add x number of users / tag, date ranges.

Is the answer "code it yourself"? I guess I could pre-crunch a lot of data and find a library to create the graphs for me.

Or is there a library/package suited to this sort of thing? I've spent some time looking at datamining applications (Splunk, SQL Server Analysis Services). But these look like interactive applications to build up queries, not something to create interactive output.

I'm not attached to any particular web tech. ASP.NET / PHP / python are all good.