Libraries.io is an open source web service that lists software development project dependencies and alerts developers to new versions of the software libraries they are using. Libraries.io is written by Andrew Nesbitt, who has also used the code as the basis for DependencyCI, a service that tests project dependencies. A key feature is that the service checks for software license compliance. On November 14, 2017, Libraries.io announced its acquisition by Tidelift, an open-source software support company, with an intention to continue to develop and operate the service.