Ask HN: What are some examples of underutilized technology?

I have come across several projects recently that have captured my attention. In particular, each project takes well-established technology/research and leverages its functionality in new and interesting ways. Here are a couple of examples:

- HTMX

HTTP and REST have been around for 20+ years. However, the industry largely settled on json and thick clients to render the ui. HTMX revisits the original concept of hypermedia and pushes state management to the server. It's a useful extension of html (written in js) that really should be part of the spec.

- LiteFS

Sqlite is a well known embedded database. However, it only scales vertically. LiteFS makes it possible to use sqlite as a distributed database and replicate changes across nodes. It combines the robustness of sqlite with modern distributed systems.

- XState

In the 80's computer scientist, David Harel, introduced statecharts. Essentially, state machines that can be nested and parallelized. This avoids state explosion in a normal state machine. Eventually, statecharts were formalized as a spec by w3c. XState is a Javascript library built on that spec that allows developers to tame complex states.

What are some other examples of technology/research that has been around for a while but may seem underutilized or is limited in its scope? What are some places to look?