H3C HEALPix library for PostgreSQL  (version 1.1.9)
About H3C

H3C is a PostgreSQL library dedicated for astronomy. The Library contains functions to index positions (ra,de) with the HEALPix and others to make a cone search or a crossmatch, it can work with circle, polygon or box.

See also
Installation guide
Licence GPL licence
H3C tuning
SQL functions