Not sure how to tag this, but it seems a request for discussion of a new interface, so probably belongs under Development.
I am wondering if anything like the Sage cell server is possible, desirable and contemplated in/for Julia?
My immediate need is for using PreTeXt to write some course material and/or books (see https://mathbook.pugetsound.edu/). The Sage cell server is a way to short bits of Sage code within a browser, usually via HTML but more generally from some XML application as is the case with PreTeXt. (See https://sagecell.sagemath.org/, https://www.sagemath.org/ and https://en.wikipedia.org/wiki/SageMath).
Madrid Autonomous University’s maths dept even have a Sage cell server anybody can call on via HTML in a web page. Bit like a tiny JuliaBox, one cell at a time and no need to log in …
My perception is that this might be difficult to do efficiently in Julia, unless the cell server is purely local and loads a number of additional packages beyond Core and Base (perhaps specified by the user setting up the server), so that when a cell runs on the server it is basically a REPL with those packages (possibly even user-defined modules) available. In that case, it would start a new REPL each time, with a new workspace, so it might have noticeable lag. Even so it might be OK for course-work interface I force my students to use ;-).