Increasingly, the face of the public library is no longer a bespectacled librarian behind an orderly desk. For many patrons the entryway to the library is now a computer screen. The era of electronic access is a Pandora’s Box filled with promise, educational riches, and challenges. To bring that access to reality, information professionals make countless decisions from the mundane to the critical that shape what a patron sees when searching for information. One of the most fundamental decisions is the choice of an integrated library system, or ILS. The ILS usually provides the online public access catalog (OPAC) and can provide much of a library’s administrative functionality. These tools affect how the information is delivered, not only in presentation but also in content. The selection of an ILS has far-reaching effects on the activities of patrons, librarians, and administrators. The authority and reputation of a library is subject to relationships made with outside interests in order to provide resources to patrons. A library’s acquisitions department is subject to commercial interests from major publishers and commercial databases (Campbell et al., 2007; Progressive Librarians Guild, 2009; The Editors of The Lancet, 2007). Budgetary constraints from funding sources put a constant limitation on a library’s ability to help its community. Relationships with local government are strained by budget, censorship, and privacy concerns (Cowan, 2005). Many of a library’s outside relationships have few alternatives. For example, unless the publishing industry can transform into a self-publishing model, it will remain in the commercial sector. The scholarly journal database companies might be disintermediated by the nascent open access movement but that remains to be seen. Funding from local governments for public libraries is unlikely to improve soon as the trend in recent years has been significant cutbacks (American Library Association, 2011a): • A majority (59.8%) of public libraries reported flat or decreased operating budgets in FY2011, up from 56.4% in FY2010 and 40% in FY2009. • Almost two-thirds (65%) of libraries anticipate flat or decreased operating budgets in FY2012. • Staff salary/benefits expenditures that had plummeted 43.2% in FY2010 only dropped 8.6% in FY2011. (American Library Association, 2011b, p. 13). Libraries have very few options to save money on publishers and database providers. There is not much more that can be cut from salaries, and funding sources are not going to increase any time soon. But there is one solution that has only recently become viable. A public library can switch its ILS to free and open source software, or FOSS. This report will draw together many sources to show that FOSS ILSs have become mainstream, reaching a 14% market share as of 2012 and achieving equivalent functionality to proprietary systems. The report argues that FOSS ILSs not only beat proprietary systems on the basis of cost, but remove unwanted outside influence, and are an appropriate choice for philosophical reasons. Included is: a timeline of published evaluations, the significant milestones, a summary of the current landscape, financial analyses, and example implementations. Case studies are presented showing public libraries that have safely made the switch to FOSS ILSs and are satisfied with the functionality. Beyond the immediate financial and practical arguments, a philosophical