Add "quick" lookup form options for particles, by:
name
pdgid
mass
Make YaPPI generate a full hyperised particle family tree, as the
default page when the servlet is called with no other parameters.
Add a link to the full particle family tree from every other page
generated by the servlet.
In the implementation, extract the presentation layer out from the
logic layer of the servlet, using for example JSP or other template
mechanisms such as XMLC. This will allow easier modification of the
interface layer, independently of the logic layer.