accompanied by useful information for users and develop- ers. Whatever the error was, a human-readable text with a little description of the problem is returned along with a numerical code to identify and handle errors automatically. Advanced search A list of compatible web services that accept a selected object stored in the user’s account has been available from the beginning of the MOWServ (18). This helps users discover new web services based on the data they wish to process and also facilitates integration of diﬀerent services. As mentioned above, eﬀorts were made to create well-designed ontology to simplify service discovery. However, service discovery has become more diﬃcult since the MOWServ platform has grown to include hundreds of bioinformatics web services and many specialized data types. For this reason, great eﬀort has been made to facilitate service discovery. Users can search for a word in the service and data type ontology branches, which mark the matches directly in the tree. For more complex service discovery, the MOWServ has been extended with a new discovery tab based on the Magallanes system (20). Magallanes is a search engine enabled to use metadata from various service metadata repositories, including the INB service catalogues. Users specify a query (for example, a word), which is matched against service and data type descriptions. These matches can be exact or approximated using Levenshtein’s text distance. If a search term does not exactly match any service, the dis- covery module automatically suggests other search terms (as ‘did you mean?’ suggestions). Results are ranked not only by their degree of matching with the search term, but also based on user selections. In the same way that the number of services has been increased, the number of ﬁles hosted in the MOWServ per user has also risen in the last years. To help users ﬁnd the right object, the ﬁle explorer has been remodelled. Using Flex technology, users can now go through the complete list of objects and order the elements by object id, task id, BioMoby type, File name or Date. These ﬁelds are also used to ﬁlter the information by date. Pipeline management Many typical bioinformatics tasks involve the execution of several services in a pipeline. This can be done with the MOWServ by executing one service and then selecting another service to further process the output. However, such pipelines can be automated with the MOWServ. Using the MyGrid’s client Taverna (21) users can create speciﬁcations on how individual services should be combined (i.e. the speciﬁcation of the pipeline). These pipelines can be uploaded to the MOWServ in the users’ accounts and later enacted (executed). Note that the MOWServ limits the pipelines allowed according to a set of requirements (Taverna 1.4 compatibility and only BioMoby services). Pipelines will beneﬁt from all the com- putational power available in the consortium: two very high-throughput multiprocessors, and the diverse set of Nucleic Acids Research, 2010, Vol. 38, Web Server issue W673 services. Earlier versions of MOWServ executed pipelines in a ‘black-box’ mode using Taverna. Currently, parsing of Taverna pipelines is still handled by the Taverna code, but enactment is handled by MOWServ. This means that the pipelines are made more robust in the sense that they can use the replicated BioMoby services in INB (several servers provide independent and redundant services). The MOWServ enactor also requires fewer resources than the previous implementation since the pipelines are split into lightweight processes during execution. Improved data editing The process of creating and editing user data has also been improved by a new graphical interface allowing users to create new data with the object editor. The editor now simpliﬁes the editing of some particular types of data such as sequences. Traditionally, BioMoby sequences contain the sequence data itself and the length. The updated editor automatically calculates the length when creating the BioMoby formatted data. Any data created using this editor can be submitted to compatible services later on. Large sets of biological data (data sets with similar data) can also be edited with a drag-and-drop interface. Users select the existing data objects they have in order to create so-called collections, which can then be sent to com- patible services. The collection editor can be used to create sub-collections out of existing collections. RESULTS To better demonstrate the MOWServ capabilities, we will walk through a typical user session (Figure 1). Detailed information on this exercise is available as Supplementary Data (http://www.bitlab-es.com/gnv5), and comprehen- sive material for training is available at the MOWServ web page. In sequence analysis, researchers are frequently faced with the problem of having to discover whether their study protein has been isolated in any new sequenced species or whether new variants have appeared in the protein databanks. Let us assume that we start with a protein sequence on the clipboard. To proceed in the standard way, identiﬁcation of the data type related to a keyword such as ‘sequence’ (or similar description of user data) is required. The Magallanes engine is able to perform this task (Figure 1A). Even the ‘Did you mean?’ module in Magallanes could manage spelling mistakes (e.g. ‘seqeunce’) and suggest a number of alternatives. The AminoAcidSequence data type will be among the results (Figure 1B). A simple click over the data type will activate the data editor GUI which, in turn, allows the user to copy and paste from the clipboard and save as an XML ﬁle (Figure 1C). A default name is suggested by MOWServ for the new object that can be modiﬁed by the user. The new object will appear in the MOWServ user objects tab and from here the user can request the com- patible services for the ﬁle in question (clicking on the ‘get compatible services’ button). The runNCBIBlastp1