There's a TeX package that, among many other features, detects rivers: https://mirrors.ibiblio.org/pub/mirrors/CTAN/macros/latex/contrib/impnattypo/impnattypo.p

There's a TeX package that, among many other features, detects rivers: https://mirrors.ibiblio.org/pub/mirrors/CTAN/macros/latex/contrib/impnattypo/impnattypo.pdf https://mirrors.ibiblio.org/pub/mirrors/CTAN/macros/latex/co... The intent here is that the document author is informed that their text contains rivers, and responds by tweaking the wording until they land on something that doesn't have them. Of course, for a browser engine this is a complete nonstarter; a useful feature for dealing with rivers would require not just detecting them but automatically removing them, without changing the text content. I'm not aware of any existing software that does this, but I've found one proposed list of exploratory directions that could make a decent starting point for anyone who wanted to build this: https://tex.stackexchange.com/a/736578 https://tex.stackexchange.com/a/736578