Why open source?

Using FOSS allows for product customization, advances interoperability between tools, and makes it possible to maintain a system with more than one administrator.

Other benefits include:

Flexible usage. The benefits of using FOSS compel 18F to meet citizen and business needs by modifying existing or creating new FOSS. FOSS is particularly suitable for rapid prototyping and experimentation. The testing process generates minimal costs, and the process encourages the identification and elimination of defects not recognized by the original development team.
Community involvement. Publicly available source code enables continuous and broad peer review. Whether simply publishing the completed code or opening the development process, the practice of expanding the review and testing process to a wider audience and beyond the development team and ensures increased software reliability and security. Developing in the open also allows for other opinions to help adjust the direction of a product to maximize its usefulness to the community it serves.
Cost-savings. The ability to modify FOSS makes it easier to respond rapidly to changing missions and markets. Support and maintenance of open source code provides a real cost advantage where multiple software licenses may be required. The total cost of ownership may be shared with a community, rather than solely the Federal government.
Reusability. The code created through American tax dollars belongs to the American people as a part of the public domain. However, the end-product is not the only way they should be able to interact with their government. By coding in FOSS, we help populate a larger commons that cities, states, businesses, and citizens can participate in. This creates real economic value by lowering the burden of replicating similar work or by allowing the private sector to build off of and create new businesses around code developed at.