Ian: "There's also Nevow, for another ZPT-style templating system."
Nitpick: I think this mischaracterises Nevow somewhat, as there's a significant difference in how Nevow (specifically Nevow.renderer) and ZPT work. While ZPT keeps its basic flow control structures into HTML templates, Nevow does all flow control from Python via a programmatic interface. Templating systems like Nevow, PyMeld and my HTMLTemplate are conceptually closer to DOM and desktop-GUI systems than to macro-descended/influenced embedded templating language-based systems like PHP, Cheetah, TAL, etc.
(Historical note: It was actually ZPT that gave me the original idea for HTMLTemplate. I just took the custom tag attributes and callback-into-Python concepts, boiled them down as far as they could go, and fused them to what I already knew about DOM and application scripting.)
BTW, I'm not sure why the paper's author classes STL with PyMeld, as STL falls into the embedded language camp. He also seems to suggest that PyMeld is templating language-based, which it's not. Anyway, I thought the paper read more like a puff-piece for STL than a objective assessment of the full templating engine arena. Not that I object to puff per-se, but I do think it should have provided a full disclosure so readers will know where the author is coming from. A pity, as with all the different templating systems currently floating about it would be nice to have a really good, objective comparison to help both developers and users judge their pros and cons better.