Best cleint side open source technologies for visully rich content

I am planning to make a data-intensive website which should be visually rich with graphs, bar charts, heatmps etc. Also these graphs need to be interactive, i.e. it should show underlying data on mouse hovers or say provide slider like options that defines time period of the data shown( 18 years or 15 years or just 3 years etc) or compare two sets of data by plotting together etc.

Further I don't have much fund to my disposal so open-source or free-to-use technologies are better, atleast for POC and evaluation. Following are some questions I have.

What are the best tools to do this at client side? Any pointers will be helpful.