Billed by the vendor as a "Universal Server," Virtuoso combines and consolidates the features of multiple individual server platforms.

At its core, Virtuoso is a database engine; it includes its own SQL-ready Object-RDB, as well as supports connections to and aggregation of multiple, disparate external DBs via support for ODBC, JDBC, UDBC, and OLE-DB connections, as well as support for XML and free text data sources and HTTP-accessible sources. Virtuoso enables clients to provide single SQL queries that join data from multiple and different data sources; any sources that the product itself can access via the mechanisms described above. Under the hood, Virtuoso is aware of each of the connected DB's capabilities and is able to mask differences by sending only SQL queries that the external DB is capable of performing--with Virtuoso itself then performing the remaining portions of the SQL query on the returned data. The vendor states that Virtuoso prefers to send queries directly to the external DBs "as is" whenever possible; but is additionally able to apply such features as path optimizations and hash joins for multi-DB queries.

Native XML capabilities are baked into Virtuoso, including storing XML data in its native form and supporting the transformation of SQL queries against legacy DBs into XML documents for the results. An XSL-T processor, XML Schema validator, and XQuery/XPath query processor are also listed as standard features.

Data in Virtuoso--either data stored in its own DB or data that is accessible via connections to remote DBs--is exposed through multiple potential interfaces; including client ODBC, JDBC, .net data provider and OLE/DB connections; as well as SOAP (Web Services) and HTTP-based connections. Its ability to expose data via these multiple possibilities--in addition to its ability to host multiple scripting language bridges (PHP, Ruby, Perl, etc.) each with direct access to stored data; its own native stored procedure support (Virtuoso PL); and support for its own dynamic Web page development format (.vsp/.vspx)--are some of the features that fuel the vendor's "Universal Server" claim. Other features on this front include E-mail integration (SMTP agents can write data to Virtuoso stores; and the DB itself can operate as a POP3 server for stored messages); WebDAV support for both data publishing and consuming; and support for a server-wide URL namespace.

Other key features of Virtuoso include support for RDF and SPARQL; support for data replication and synchronization, including bi-directional replication between SQL Server, Oracle, and DB2; and BPEL support.

Virtuoso is deployed on a Windows (2000/XP/2003), Linux (Red Hat, SuSE), or UNIX server. And new to the platform is the availability of a pre-configured edition of Virtuoso as an Fedora-Linux based Amazon Machine Image for deployment and use in the Amazon EC2 cloud.

Virtuoso is available now, in Personal and Enterprise flavors with multiple licensing breaks ranging from $1,240 per server CPU (workstation license, five concurrent DB connections) to $249,433 per server CPU for unlimited DB connections on a workstation license. Application server licensing is also available.

Visit the OpenLink Software Web site for further information.