The technology of the 21st century has had no shortage of challenges for libraries, but it has also brought opportunities. Operating systems, databases, and application environments that can use cheap off-the-shelf hardware to scale and handle hundreds of millions of transactions were not developed for libraries. However, libraries have taken advantage of these technologies with multiple integrated library systems (ILSs) now featuring this scalability. One of the best-known among these younger systems has been the Evergreen open source ILS, which was adopted in 2009 by the South Carolina Library Evergreen Network Delivery System (SC LENDS). Widespread resource-sharing library consortia, especially those powered by Evergreen, are quickly growing. With Evergreen, SC LENDS was able to begin its pilot program of 10 library systems and then scale to accommodate adding libraries as they elected to join. Investment in open source paid off for libraries beyond South Carolina, creating a single, more coherent collection out of many. This article discusses a practical approach to collection deduping.