OMERO Project Background

The OME project builds, releases, and supports open source image data, metadata, and analysis management systems. For the last six years, we have been working on the OME server, a perl-based middleware application. This system is available and extensively documented.

The OME Remote Objects Server (OMERO) began as a partial port of the OME Perl Server (OMEDS and OMEIS) to Java. The use of a Java-based server provided two major advantages:

• It replaced our customised object-relational mapping code ("DBObject") with existing object-relational mapping (ORM) tools, specifically Hibernate. This removed the burden of maintaining self-written code that was the basis of OME-perl: as new Linux versions were released, DBObject became incompatible with new versions of various Perl modules. This problem was by no means insurmountable, and DBObject was appropriately updated, but this significant code maintenance was a burden. Though DBObject worked well, there are simply other development teams who specialize in ORM and, for instance, have dedicated their efforts to providing a tool that can easily switch between different relational database management systems.
• A major goal of the Dundee group was and is the support and provision of remote client applications, allowing users to view, manage, and analyse images in a location and platform-independent manner. OMERO's design allows use of off-the-shelf tools for communication between an OME server and remote clients. OME-perl required, again, an interface called OME-JAVA, written and maintained by the OME project. This supported the OmeroShoola client on OME-perl, but was very complex, and our choice of data transport (XML-RPC), while a common standard, caused severe performance problems when large data graphs were passed from server to client. Moreover, OME-JAVA provided an interface for Java clients but no support for other languages—C++, .NET, Python, etc., that were required by the community.