A 'service' in Anno-J (often referred to as a fetcher) is is a small program that sits out on the web somewhere and responds to simple HTTP requests with sensible data. For example, a time fetcher might respond to the query: http://www.somesite.com/service?tellTime with a response of 09:30:00 AM. From the client's perspective, the fetcher's implementation details are irrelevant.
Anno-J is a client and it's important to realize that it does not store data: it is a REST-based, 100% server-side agnostic application. It is the responsibility of the data provider, not the client, to maintain, curate, secure, syndicate, and host his/her own data.
This section provides an example of how to create a server-side fetcher that provides Gene Model annotation data in response to simple HTTP GET requests (conveniently the same requests that an Anno-J GeneModels plugin uses). The example uses MySQL, PHP and Apache but does not depend upon these technologies.