XStreamDB is a database server specializing in the storage and retrieval of XML documents. It is built on Java and runs on machines that include a Java 1.4 VM.

For storage, XML documents are stored in the DB natively, while non-XML documents are stored as binary documents with their approproiate mime-types for later retrieval. XML validation is supported by the server, including the ability to load both DTDs and W3C Schemas; when a Schema is attached to a specific root, all documents that are stored within it are validated based on that Schema.

Accessing the server can be accomplished through the provided, JDBC-like API or an included separate ad-hoc application, XStreamDB Explorer. Additionally, individual documents, schemas, or binary files can be exposed as Web resources, allowing them to be accessed by WebDAV enabled clients, the XdbWeb Web application (a collection of utility servlets which expose features of XStreamDB to the Web), or a Resource API.

Locating information in the XML repository is facilitated via XQuery support, and the ability to index both specific values or fulltext documents. Fulltext searches, in particular, can be performed via wildcard matching, word proximity, or phrase matching. Various additional XQuery extensions are also supported by XStreamDB, including XSLT Transform and JDBC Connector functions.

Other features of XStreamDB include hot backup configuration support, and an MD5-based user permission scheme. Recent enhancements to the product include the addition of an XML Editor to XStreamDB Explorer, and the enhancement of fulltext "Scoring" such that it will now work with or without an actual fulltext index.

New features in the latest XStreamDB release include performance improvements via precompiled XQuery functions (according to the vendor operations are improved up to 30x in some cases); the addition of group security; the ability of applications to define their own operations on documents that can be managed (security-wise) by XStreamDB; enhances tree update; and document metadata support.

XStreamDB is available in a development only version ($500/seat), a version limited to 50MB of storage ($1,300/server), and an unlimited storage version ($3,000/server). A free version is available for instructional/educational use only.