The Lens, started as Patent Lens 15 years ago, is open, free, no advertising (secure) and a public service. It searches in over 90+ jurisdictions and hosts 100M patent records. It is not just federated search, but comprehensive links, analysis, embedding and sharing of records, collections and annotations.
It is run by a global social enterprise, Cambia and a publicly funded University, Queensland University of Technology (QUT).
It also has uniquely over 15M non-patent literature citations linked to canonical sources, to seek and explore prior and enabling art.