National Biomedical Computational Resource (NBRR) have announced the release of Opal plugin for Taverna 2.2.

The Opal toolkit provides a mechanism to wrap up existing scientific applications rapidly as Web services, and expose them to various clients. The implementation provides features such as scheduling (e.g. using Condor and SGE via Globus or DRMAA) and security (using GSI-based certificates).

Furthermore, the service provides job and data management (by executing every job in a separate working directory), and state management (by storing the service state via Hibernate into a database such as HSQL, PostgreSQL, MySQL or DB2). The application developer specifies a configuration for a scientific application and deploys the application as a service following a small sequence of steps. End-users can now access this application remotely as a SOAP-style Web service interfaced by the service’s WSDL document and can invoke it as part of Taverna workflows.

The Opal-Taverna plugin allows the user to use any Opal 2.x services from Taverna and construct workflows based on Opal services.

Documentation for the Opal-Taverna plugin can be found at:
https://www.nbcr.net/pub/wiki/index.php?title=Taverna

Also see:
Ren J, Williams N, Clementi L, Krishnan S, Li WW. “Opal web services for biomedical applications”, Nucleic Acids Res. 2010 Jul; 38 (Web Server issue): W724-31.