For starters, the menu is built from the xymonmenu.cfg template in the server’s etc folder.
Then, the header and footer files are in the server’s web folder: stdnormal_header and stdnormal_footer. There’s lots of others as well, and they have a lot in common, so you could optimize the pagegen code a little (but don’t, better to redo the whole presentation thing all together then, which I may end up doing later..)
Finally, the body is generated by the xymongen pagegen code. And even though to me and most text based OS users/admins that’s ok, for the graphical OS community, it’s crap. Period.
So, that’s how I ended up going the rest api route.
Nothing fancy, but a little less painful to the eye (fonts also changed in the meantime):