In Star Trek, whatever happened to the exocomps?
I recall that they were in an episode that showed them as sentient, but never saw them again.
Source: "Exocomp", Memory Alpha
It would seem they were promptly forgotten. Too bad, as they are a reference to one of my all-time-favorite Anime, Dirty Pair.
There are other examples of strange things gaining intelligence in the ST universe, a list you can see here.
Some Highlights:
Whilst the Exocomps aren't seen again in the TV show they do make an extensive appearance in the Trek Book Immortal Coil in which two exocomps (named Winken and Blinken) are key players in a plot to uncover an ancient artificial intelligence. The book states that their civilisation has joined the Federation as full members.
This was later backed up in the Star Trek: Online MMO game where they were described as being
"sentient members of the Federation"
...that were strongly aligned to Starfleet and available as members of your crew in both civilian and military modes.
Star Trek: Lower Decks (which is canon-ish) featured an Exocomp who was a member of Starfleet