Any game from an engine not listed here in the stats page can be extracted with normal extraction tools and processed with a text editor that understands regex find/replace.
Lucifen Library oretsuba etc.
Silky nanarin etc.
TamoGameSystem leyline, flyable heart, etc
2XT-PJADV nanatsuiro drops, tarareba, etc
Majiro katahane, sukinara, etc
Willadv shirokuma bell stars, etc.
ExHIBIT mittsu houhou, etc.
BGI (old) itsusora etc
BGI (new) magical charming, etc
* FVP hoshimemo etc
* igscript innocent gray games, flowers etc
krkr kirikiri; fate/stay night, yuzusoft games, alcot games, etc. very popular, hard to dump scripts from, especially new encrypted titles.
mscenario hanahira etc
* RScript steampunk and other liar/rail-soft games, and others
Koichoco (never checked the name of this engine)
* Not my code.
Nitroplus's engine: The "old" version is an HTML-esque monstrosity with bad tag name rewriting (closing tags with one name and ending them with another because they're aliased to the same tag). The "new" version is a lot cleaner, but is also an HTML-esque monstrosity.
AdvTry: Imperative text. Regex friendly but there are several non-obvious cases.
Musica: e.g. trinoline. Imperative text. Regex friendly.
QLIE: e.g. biman. Imperative text. Regex friendly.
Malie: Aside from one game that has an additional extra encoding set, these are just the script text in whatever its encoding is delimited by control characters. Extraction is the hard part. For Dies irae, I extracted the script binary from memory with a hex editor. Yeah, really. For the other Malie games, the script binaries were donated to me, and I know nothing about the details of their extraction.
PSB-using krkr games: You want https://github.com/number201724/psbfile
Siglus: I actually haven't managed to rip from these games yet. None of the tools I've found work properly on my machine or something.