We have made observations on the long-term availability of Web services that were published in the Nucleic Acids Research Web Server Issues since 2003. We investigated how many of the published services are still available and how they are managed. We directly asked the Web service authors questions about development and maintenance of their services and what kinds of problems they perceive when using someone else's Web service. We also asked them to estimate the number of visitors their service receives per month.
Our results can provide information for researchers currently building a Web service. Users generally prefer services that provide example data, help texts and communication channels to other users and the developers. Journals publishing articles about Web services should mandate the presence of all of these points before accepting a submission, and communicate this to authors and reviewers. We recommend that authors use a permanent Web address to reference their service, so they can transparently move it to a new Web server if need be. Authors should also deposit functional source code in a public repository or provide a virtual machine image to run the service from.