The Sponsoring Consortium for Open Access Publishing in Particle Physics (SCOAP3) has published its 10,000th article.
Here's an excerpt from the announcement:
SCOAP3 celebrates the publication of its 10,000th Open Access article. Since the start of its operation in 2014, the initiative has supported Open Access publication of High-Energy-Physics articles in 10 high-quality peer-reviewed journals. More than 18,000 scientists from over 90 countries have benefited from this initiative without any financial or administrative burden, retain copyright of their work and automatically comply with their institutional or funders Open Access mandates.