I remember getting one or two of this trilogy from my local library when I was young, around the early 1990s.
The plot somehow involves humans from some sort of human navy or fleet infiltrating an alien society who have distinctly feline characteristics. I seem to remember that they have retractable claws. The aliens I think are at a pretty primitive level. The humans were more advanced but I remember that one of the 'advanced tech' of the humans is the ability to program memory.
I can't remember the plot too well, the humans could have crashed on the planet, or been sent there to deliberately infiltrate the society. Can anyone identify the books based on these fragments?