It would all require server-side APIs. I've been pretty strict about not implementing APIs for sites, because it's always been my view that these will change in the future, causing sites to break. If you look at older sites, it's always guestbooks and forums that are the things broken on the site. I want sites to work for a long time. That said, you can always use 3rd party sources for these things if you want.
That is not dead which can eternal lie. And with strange aeons even death may die. :O
From what I've seen, special sauce is just people who are active and update a lot.
other things, i would like to ask you to review the function of activity. i think it's not too convenient for users to find out the history of the modification. for example, if i want to find out any date of modification, i need to browse page by page. sometimes two or more different timing of activities will be combined together. perhaps we have to make it better. thanks again.
Edit/create your not_found.html file