Mix workflow/wiki

Hi everyone,

First, I'm sorry if I make mistakes but I'm French ;)

I'm here because i've to develop a web tool to create a "tree of knowledge". This tool isn't juste a workflow, it must have a search button to access to a specific "tree" and have the possibility to create web page..

To be more understandable, here an example : I've this problem to solve : my cat seems sick. Graphically, it's what I need to implement on my tool :

So, tu summary :