From Addgene’s website:
Addgene is a nonprofit plasmid repository located in Watertown, MA. Addgene’s mission is to accelerate research and discovery by improving access to useful research materials and information. Addgene facilitates the sharing of high-quality scientific materials, research reproducibility, and open science by archiving and distributing DNA-based research reagents and associated data to scientists worldwide. Addgene’s repository contains over 65,000 plasmids, including special collections on CRISPR, fluorescent proteins, and ready-to-use viral preparations. Addgene offers free online educational resources and protocols about molecular biology such as common vector backbones, cloning, CRISPR, and AAV and lentiviral plasmids.