It is built on java, front-end html css javascript, bootstrap, reactjs. Charting used is C3 and D3 which is extensible.
You can create reports, dashboards and other data analysis from your databases, flat-files, big data, graph databases, column databases etc and share with users, export, implement alerting, email scheduling and many more exciting features. Helical Insight is a framework, thus there a lot of placeholders, APIs, SDK and source-code allowing you to extend functionalities. Use HTML,CSS and java resources to extend functionality at front-end and back-end respectively. We are also having a rule engine allowing things like BI automation, alerting notification, actionable reports etc.
GitHub link : https://github.com/helicalinsight/helicalinsight Details : http://www.helicalinsight.com/helical-insight-ce/
Please do check out and give us your valuable feedback.