spinneret VS markup

Thirteen Letters - front end uses parenscript, spinneret, and cl-css; back end uses hunchentoot/hunchensocket

That looks more like an Emacs Lisp equivalent to CL's Spinneret than a renderer. Quite nice, but also not quite the same use-case.

Obviously this is a contrived example, but the point is that I want to generate HTML from a list. I don't care about compiling, DSLs or templates, just a plain nested list. Spinneret seemed like it would fit the bill because it has the function interpret-html-tree, but then the author made the entire library only work with a set of hard-coded tags, so if my list contains the math tag (which is a standard HTML5 tag) everything fails.

spinneret

Correct. Php mode focuses on not mixing php and html which is the more modern suggested way. Multi major modes can be fun, but very difficult to get to work correctly, especially for indentation. OP, if you really want this to work, php mode will need soecial treatment like js-mode for jsx or something like this: https://github.com/moderninterpreters/markup/blob/master/lisp-markup.el which is a minor mode for writing html in lisp files.

Also, /u/KaranasToll wrote an Emacs mode for markup, which I also can't live without: https://github.com/moderninterpreters/markup, basically the ability to indent HTML embedded inside CL.

Very nice! Then I wonder how much it is doable to add a JSX-like syntax, such as https://github.com/moderninterpreters/markup (so that we could copy&paste HTML snippets).

Heavy use of markup, most files have at least some HTML interspersed with Lisp. This might go against everything you've learnt about software design, but works really well.

Finally, if you like React style HTML-in-js, you might also like HTML-in-Lisp: https://github.com/moderninterpreters/markup

Let me give you an example. In PHP, Facebook wanted the ability to write HTML inside PHP code, so they built that feature into their PHP compiler (and through some series of steps eventually became HHVM, which isn't technically considered PHP anymore, but I digress). Similarly, they wanted that feature for Javascript so they modified their compiler to support that. I've worked for Facebook, and I loved that feature and missed it when I left. So I built that for Lisp: I just wrote a reader macro without changing the compiler, and I had a working implementation in a day's work. (Btw, the library is here: https://github.com/moderninterpreters/markup)