Grafana - Data visualization & Monitoring with support for Graphite, InfluxDB, Prometheus, Elasticsearch and many more databases
D3.js - D3.js is a JavaScript library for manipulating documents based on data. D3 helps you bring data to life using HTML, SVG, and CSS.
Dashing.io - The exceptionally handsome dashboard framework
Highcharts - A charting library written in pure JavaScript, offering an easy way of adding interactive charts to your web site or web application
Smashing - Smashing is a fork of Dashing (which is no longer maintained), a Sinatra based framework that lets you build beautiful dashboards.
Chart.js - Easy, object oriented client side graphs for designers and developers.