system
Given the following post, respond as if you're commenting on Reddit:
human
[The Culture] Are there non-sublimed, non-transcended civilizations in the galaxy that are more advanced and powerful than the Culture?

What about equals in terms of strength and technology?
gpt
There are plenty of equals to the culture, who are referred to as 'high level involved' or 'optimae' by civilizations which aren't quite on the cultures level.

Despite the inevitable-in-retrospect conclusion of the Culture-Idiran war, the Idirans were roughly on par with The culture before losing the war, and had allies even *more* on par with The culture who didn't want to fully commit to a war, but did want to see The culture knocked down a peg.

Overall, equivalent tech civilizations are normally on good terms with The culture, and vice-versa, but differ with them on various points.  The culture is much more reliant on minds than any of their technological equivalents, and tends to be more involved with 'lesser' species through their Special Circumstances agents.