At one point in time, Ardour (x-platform, FLOSS DAW) let you directly search and download from Freesound within the program.
We stopped doing that when their authentication API changed. They've subsequently changed it to something that would allow the functionality to be restored, but nobody has found the time to do that yet.
https://github.com/ffont/FreesoundSimpleSampler - demonstrates the use of the freesound-juce API client; the user can create a textual query to Freesound.org and 16 random sounds are loaded in a sampler.
And publications: https://scholar.google.com/scholar?q=freesound
I believe it's managed by the Music Technology Group at Universitat Pompeu Fabra https://www.upf.edu/web/mtg
You can support it with donations: https://freesound.org/donations/donate/