We present iTowns, a web framework developed in Javascript / WebGL for 3D geospatial data visualization, with capabilities for precise measurement directly in the browser. The first use case of iTowns is Street-view data type visualization : immersive images, but also terrestrial LIDAR Point Cloud data. But iTowns now supports much more data types :  Oriented images Panoramic images Point Clouds 3D textured models WFS vector data iTowns OpenSource is the descendant of the initial iTowns software developed at MATIS research laboratory of the French National Mapping Agency. iTowns OpenSource version 1.0 has been released in February 2016. The framework allows to : - Visualize projected images on a mesh ( cube, 3D model) - Visualize panoramic images - Display depth panoramic images - Display extruded building ( from WFS, other sources ) - Navigate in 3D (click & go) - Display Point Clouds - Visualize textured 3D models ( B3D, 3DS) - Use a simple API We detail iTowns features with videos. The data showcased was acquired by IGN's Stereopolis car. Aside from presenting the software, its present state and the future 2.0 version, we also explain the project history, which is an interesting case of technology transfer from research to industry.