3Sixty is a desktop software for creating 360 virtual tour websites. It provides visual tools for adding panorama images, placing hotspots and attaching useful actions to each of them.
So 3Sixty Web Tour Maker is a free and open source software built using another free open source software. 3Sixty is completely free and will always be.
To view the source code, click here: https://github.com/habibieamrullah/3Sixty-WebTour-Maker
Any question? You can send me an email to habibieamrullah-at-gmail-dot-com