Here is the problem: you cannot do it. Nobody can, because what is called a "family tree" is not a tree. A tree is by definition a graph without loops. A family relationship graph does have loops by a simple reason: everyone has both father and mother, and in a tree, a note only has a "parent node".
So, there is no such thing as "family tree". Nobody can create something which cannot exist. :-)
I have an opinion why this thing is still called "family tree". I think the concept was created when females was not counted, so it was really a tree, with only paternal lines shown. Not sure though, may be my knowledge of history of this phenomena is poor.
Now, the question is: how to create a family graph? This would be quite a job which needs thorough design and considerable time. I can see two basic features to be used here:
- HTML5 Canvas.
See http://en.wikipedia.org/wiki/Canvas_element[^], https://developer.mozilla.org/en/Canvas_tutorial[^] - SVG which can be embedded in HTML5 or used in HTML tags
object
or embed
.
See:
http://en.wikipedia.org/wiki/Scalable_Vector_Graphics[^], http://www.w3schools.com/svg/svg_inhtml.asp[^].
See also:
http://dev.opera.com/articles/view/svg-or-canvas-choosing-between-the-two/[
^].
—SA