Seniors Serving Seniors and Seniors Serving Society (SSS) Seniors Serving Seniors and Seniors Serving Society is an international volunteer program developed within Holiday Retirement Corp., the world’s leader in senior housing. It was developed to provide opportunities for all 35,000 residents and 10,000 employees, to sustain the foundation of the company’s Grass Roots, which is to serve seniors, each other, and society. This site is brought to you by Holiday Retirement Corporation and XL Managment Company.