ROOT I/O in JavaScript

In order to be able to browse (inspect) ROOT files in a platform independent way, a Java Script version of the ROOT I/O subsystem has been developed. This allows the content of ROOT files to be displayed in most available web browsers, without having to install ROOT or any other software on the server or on the client. This gives a direct access to ROOT files from any new device in a lightweight way. It is possible to display simple graphical objects such as histograms and graphs (TH1, TH2, TH3, TProfile, and TGraph). The rendering of 1D/2D histograms and graphs is done with an external Java Script library (D3.js), and another library (Threejs) is used for 2D and 3D histograms. We will describe the techniques used to display the content of a ROOT file, with a rendering being now very close to the one provided by ROOT.