RoboPol's AGN polarimetric monitoring data 2013 -- 2017 are public.
Monitoring data for stars in the RoboPol's sample of optical polarimetric standards is here.
Project's deki page is here.
Project's logos are here.
Links to external polarimetric data sources:
University of Arizona optical polarimetry monitoring data for Fermi blazars is here.
A compilation of optical polarization catalogs - arXiv:2307.05752