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Epi-Info Goes Open Source™

by Jay Jones

Epi Info™ logoNCPHI’s Epi Info™ team recently released the application’s code to the public, making it the first PHIN application to go open source. “Because the code is out there, other developers and other entities can use the Epi Info™ code to add features, contribute enhancements, and make it a much better product,” according to Enrique Nieves, Acting Division Director for the Division of Integrated Surveillance Systems and Services responsible for the Epi Info™ open source project. Enrique adds: “Going open source will also help us grow a wider user base, and as we grow, we will attract more users who want to help with development.”

The Epi Info™ user base is already quite large, with over a million users worldwide. In its twenty-year existence, many CDC developers and contractors have worked on Epi Info™, resulting in code that needed to be updated to bring it up to today’s real-time, Internet-age standards and to make it suitable for release to the open-source community of developers. The Epi Info™ code is comprised of many components, including Visual Basic, Access, SQL, C#, etc.

To ensure a successful transition to open source, there are currently three versions of Epi Info™. Epi Info 3.5.1 is the latest release of the application and has been deployed to the Epi Info user base. Epi Info 7™ and Epi Info Community Edition (CE) share identical code; however, Epi Info 7™ is being developed at the CDC and Epi Info CE has been posted on the Web for open-source developers to use.

  • Epi Info 3.5.1™: The current version of Epi Info™ is the final version to be released to its user base using the existing code.
  • Epi Info 7™: This next version of Epi Info™, is currently in the early stage of the development process (Pre-Beta version). Epi Info 7™ will replace version 3.5.1 and will include modules and other enhancements created and/or suggested by the open source community.
  • Epi Info Community Edition (CE): Epi Info 7™ code that has been released to the open source community. Epi Info™ CE will be developed independently from Epi Info 7™ by the open source community, who will then submit code contributions to the CDC for consideration of inclusion in Epi Info 7™.

“.NET™ is a very difficult program to move to open source, so we created Epi Info CE outside the CDC firewall; the new code that is developed by the open source community does not cross back over the firewall to CDC,” says Nieves. The versions of Epi Info™ that are inside Photo: Enrique Nievesthe CDC firewall (3.5.1. and Epi Info 7™) have to meet strenuous federal security requirements. Nieves says that they put Epi Info™ CE outside the CDC firewall so that they “could use the world as our development laboratory. Now, users who have access to Epi Info CE can develop and send us information about their contributions. We can then evaluate it and determine if it is something we can incorporate into Epi Info 7™. If it is, we then put it through CDC and other federal security requirements.” This process will ensure that CDC/NCPHI takes the best of what the open-source community offers while maintaining an application that meets federal security requirements for its Epi Info™ user base.

The process is not cyclical. The Epi Info™ team will receive code enhancements from the community, but they will not update the code and return it to the open source community. This process is necessary to ensure the application continues to meet federal security requirements and is vetted by the CDC before it goes to the existing user base. Eventually, there will be a fork in the two development efforts: Epi Info CE will be one product, and CDC’s Epi Info 7™ will be a CDC-supported product that meets federal security requirements.

However during the entire process, the communication and evaluation will be ongoing and bi-directional. Nieves says that “right now, we’re working on the communication process between the users and us. We have a Web board for users to submit their enhancement ideas. There is also another board called MyEpiInfo, which is completely independent and supplies a forum for developers to collaborate.”

Though still very early in the process, Nieves’ division is currently working on a draft document that describes how they took Epi Info™ to open source, which includes the collaborative work they did with CDC’s Office of General Counsel in reviewing various open source licenses to consider the most appropriate one for CDC.

In the future, Epi Info™ may be the Microsoft Office of epidemiology, a suite of products for outbreak management. The major difference is that it will be created by user feedback and contributions in an open source environment.

Enrique adds: “As long as users know how to compile code, they can go and compile the Epi Info CE code, load it into their computer, and begin working. There still are some high-level statistical modules that we are now beginning to add to Epi-Info 7™. But if you want to develop a database, it’s ready to go.”

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