I built this website because I wanted a privacy-focused way of sharing a family tree. The result is static website that loads a GedcomX file from your disk, parses it and shows you the family tree. There is no logic on the server side other than providing the JavaScript, HTML and CSS files.
However, the website is currently unable to create and edit the family tree. For this, I have a simple spreadsheet that is converted to the GedcomX-JSON format through a Python script.
The graph is rendered using d3 together with WebCola to position the nodes.