I made one for a single page that I wanted to template nicely without introducing dynamic pages (wasteful since it's always the same file anyway) or JavaScript (wasteful since the layout is always the same anyway)
I'll probably do another one again soon, just so I don't have to rewrite my HTML / RSS by hand to publish another post.
Lua is a nice data language, so I just put the data and the code and the HTML fragments into one Lua file, no more than 200 lines. No worries about injection since it's all my data with no backend code at runtime.