https://www.latinum.org.uk/shadowing/interlinear-method lists various old interlinears. Though even for the Latin-English interlinears it's not complete: for example it's missing the gonzo Completely Parsed series (eg. Gallic War chapter 1: https://archive.org/details/CommentariesOnTheGallicWarCaesar... ), and the Fully Parsed me-too series. I'm working on a summary of the old Latin-English and Latin-Ancient Greek interlinears but I don't know when it will be finished.
Seemingly there's still no proper file-format supporting interlinears. Naturally enough: they're not straightforwardly recursive and tree-structured so the computing world's main response is to pretend that they don't exist lolz. (Paging Ted Nelson.) But it seems that interlinears are still very much in use among some research communities in linguistics, so every few years someone puts out a plaintive paper begging for someone to do something about the lack of a proper file format, see eg. https://aclanthology.org/L04-1143/ and https://dl.acm.org/doi/10.1145/3389010 , and then of course nothing happens.
There are two modern commercial publishers I'm aware of which specialise in interlinears: https://hyplern.com and https://interlinearbooks.com/ .
Some people transcribed one of the Hamilton et al. interlinears, Cornelus Nepos' Vitae, into WikiSource: https://la.wikisource.org/wiki/Cornelii_Nepotis_Vitae_(Hamil... .
More modern (for the most part) but not at all unrelated: parts-of-speech tagging https://en.wikipedia.org/wiki/Part-of-speech_tagging and treebanks https://en.wikipedia.org/wiki/Treebank . https://syntacticus.org/ has a UI which is almost usable for learning-by-reading: https://syntacticus.org/sentence/proiel:20180408:caes-gal:52... . (The Perseus DL also has a classical-Latin treebank: https://perseusdl.github.io/treebank_data/ .)
Seemingly there's still no proper file-format supporting interlinears. Naturally enough: they're not straightforwardly recursive and tree-structured so the computing world's main response is to pretend that they don't exist lolz. (Paging Ted Nelson.) But it seems that interlinears are still very much in use among some research communities in linguistics, so every few years someone puts out a plaintive paper begging for someone to do something about the lack of a proper file format, see eg. https://aclanthology.org/L04-1143/ and https://dl.acm.org/doi/10.1145/3389010 , and then of course nothing happens.