XQuery序列规范更新！
2004.10.29日，XQuery序列规范再次更新，此次更新的有：XQuery 1.0: An XML Query Language, XML Path Language (XPath) 2.0, XQuery 1.0 and XPath 2.0 Functions and Operators, XSLT 2.0 and XQuery 1.0 Serialization, XQuery 1.0 and XPath 2.0 Data Model.
新版本的变化如下（仅列出目录部分）：
上一版本（2004.7.23）
最新版本（2004.10.29）
2 Basics
2.1.1 Static Context
2.1.2 Dynamic Context
2.2 Processing Model
2.2.1 Data Model Generation
2.2.2 Schema Import Processing
2.2.3 Expression Processing
2.2.3.1 Static Analysis Phase
2.2.3.2 Dynamic Evaluation Phase
2.2.4 Serialization
2.2.5 Consistency Constraints
2.3 Documents
2.3.1 Document Order
2.3.2 Atomization
2.3.3 Effective Boolean Value
2.3.4 Input Sources
2.4 Types
2.4.1 Predefined Types
2.4.2 Typed Value and String Value
2.4.3 SequenceType Syntax
2.4.4 SequenceType Matching
2.4.4.1 Matching a SequenceType and a Value
2.4.4.2 Matching an ItemType and an Item
2.4.4.3 Element Test
2.4.4.4 Schema Element Test
2.4.4.5 Attribute Test
2.4.4.6 Schema Attribute Test
2.5 Error Handling
2.5.1 Kinds of Errors
2.5.2 Handling Dynamic Errors
2.5.3 Errors and Optimization
2.6.1 Schema Import Feature
2.6.2 Static Typing Feature
2.6.3 Full Axis Feature
2.6.4 Module Feature
2.6.5 Pragmas
2.6.6 Must-Understand Extensions
2.6.6.1 XQuery Flagger
2.6.7 Static Typing Extensions
2.6.7.1 XQuery Static Flagger
2.7 Comments
3.1.1 Literals
3.1.2 Variable References
3.1.3 Parenthesized Expressions
3.1.4 Context Item Expression
3.1.5 Function Calls
3.2 Path Expressions
3.2.1 Steps
3.2.1.1 Axes
3.2.1.2 Node Tests
3.2.2 Predicates
3.2.3 Unabbreviated Syntax
3.2.4 Abbreviated Syntax
3.3.1 Constructing Sequences
3.3.2 Filter Expressions
3.3.3 Combining Node Sequences
3.5.1 Value Comparisons
3.5.2 General Comparisons
3.5.3 Node Comparisons
3.7 Constructors
3.7.1 Direct Element Constructors
3.7.1.1 Attributes
3.7.1.2 Namespace Declaration Attributes
3.7.1.3 Content
3.7.1.4 Whitespace in Element Content
3.7.2 Other Direct Constructors
3.7.3 Computed Constructors
3.7.3.1 Computed Element Constructors
3.7.3.2 Computed Attribute Constructors
3.7.3.3 Document Node Constructors
3.7.3.4 Text Node Constructors
3.7.3.5 Computed Processing Instruction Constructors
3.7.3.6 Computed Comment Constructors
3.7.4 In-scope Namespaces of a Constructed Element
3.8.1 For and Let Clauses
3.8.2 Where Clause
3.8.3 Order By and Return Clauses
3.8.4 Example
3.9 Ordered and Unordered Expressions
3.12 Expressions on SequenceTypes
3.12.1 Instance Of
3.12.2 Typeswitch
3.12.3 Cast
3.12.4 Castable
3.12.5 Constructor Functions
3.12.6 Treat
3.13 Validate Expressions
3.13.1 Validating an Element Node
3.13.2 Validating a Document Node
4.4 Default Collation Declaration
4.7 Default Namespace Declaration
4.8 Default Ordering Declaration
4.9 Schema Import
4.10 Module Import
4.12 Variable Declaration
4.13 Function Declaration
2 Basics
2.1.1 Static Context
2.1.2 Dynamic Context
2.2 Processing Model
2.2.1 Data Model Generation
2.2.2 Schema Import Processing
2.2.3 Expression Processing
2.2.3.1 Static Analysis Phase
2.2.3.2 Dynamic Evaluation Phase
2.2.4 Serialization
2.2.5 Consistency Constraints
2.3 Error Handling
2.3.1 Kinds of Errors
2.3.2 Identifying and Reporting Errors
2.3.3 Handling Dynamic Errors
2.3.4 Errors and Optimization
2.4 Concepts
2.4.1 Document Order
2.4.2 Atomization
2.4.3 Effective Boolean Value
2.4.4 Input Sources
2.5 Types
2.5.1 Predefined Types
2.5.2 Typed Value and String Value
2.5.3 SequenceType Syntax
2.5.4 SequenceType Matching
2.5.4.1 Matching a SequenceType and a Value
2.5.4.2 Matching an ItemType and an Item
2.5.4.3 Element Test
2.5.4.4 Schema Element Test
2.5.4.5 Attribute Test
2.5.4.6 Schema Attribute Test
2.6.1 Schema Import Feature
2.6.2 Static Typing Feature
2.6.3 Full Axis Feature
2.6.4 Module Feature
2.6.5 XML and Names 1.1 Feature
2.6.6 Pragmas
2.6.7 Must-Understand Extensions
2.6.7.1 XQuery Flagger
2.6.8 Static Typing Extensions
2.6.8.1 XQuery Static Flagger
2.7 Comments
3.1.1 Literals
3.1.2 Variable References
3.1.3 Parenthesized Expressions
3.1.4 Context Item Expression
3.1.5 Function Calls
3.2 Path Expressions
3.2.1 Steps
3.2.1.1 Axes
3.2.1.2 Node Tests
3.2.2 Predicates
3.2.3 Unabbreviated Syntax
3.2.4 Abbreviated Syntax
3.3.1 Constructing Sequences
3.3.2 Filter Expressions
3.3.3 Combining Node Sequences
3.5.1 Value Comparisons
3.5.2 General Comparisons
3.5.3 Node Comparisons
3.7 Constructors
3.7.1 Direct Element Constructors
3.7.1.1 Attributes
3.7.1.2 Namespace Declaration Attributes
3.7.1.3 Content
3.7.1.4 Whitespace in Element Content
3.7.2 Other Direct Constructors
3.7.3 Computed Constructors
3.7.3.1 Computed Element Constructors
3.7.3.2 Computed Attribute Constructors
3.7.3.3 Document Node Constructors
3.7.3.4 Text Node Constructors
3.7.3.5 Computed Processing Instruction Constructors
3.7.3.6 Computed Comment Constructors
3.7.4 In-scope Namespaces of a Constructed Element
3.8.1 For and Let Clauses
3.8.2 Where Clause
3.8.3 Order By and Return Clauses
3.8.4 Example
3.9 Ordered and Unordered Expressions
3.12 Expressions on SequenceTypes
3.12.1 Instance Of
3.12.2 Typeswitch
3.12.3 Cast
3.12.4 Castable
3.12.5 Constructor Functions
3.12.6 Treat
3.13 Validate Expressions
3.13.1 Validating an Element Node
3.13.2 Validating a Document Node
4.4 Default Collation Declaration
4.8 Empty Ordering Declaration
4.9 Inherit-Namespaces Declaration
4.10 Schema Import
4.11 Module Import
4.13 Default Namespace Declaration
4.14 Variable Declaration
4.15 Function Declaration
这一版本最大的变化是把原来的错误处理（2.5 Error Handling）提到了2.3节，而且加了一些东西。另外，在最后一节（4. Modules and Prolog）中，新增了两节： 4.7 Ordering Mode Declaration 和 4.8 Empty Ordering Declaration，其他部分行文作了一些修改，变化不大。
与此同时，也更新了几个实现，截至到目前，官方公布的XQuery的实现包括：
W3C's Grammar Test Pages:
The XQuery 1.0 Grammar Test Page for the 29 Oct 2004 specification (updated)
(previous versions: for the 23 Jul 2004, 12 Nov 2003 and 2 May 2003 specifications)
The XPath 2.0 Grammar Test Page for the 29 Oct 2004 specification (updated)
(previous versions: for the 23 Jul 2004, 12 Nov 2003 and 2 May 2003 specifications)
AGiLiENCE's XPeerion
BEA's Liquid Data
Berkeley Lab's Nux, an open source XQuery extension to XOM.
Blackpearl's Blackpearl 4 platform, with an embedded XQuery engine
Bluestream Database Software Corp.'s XStreamDB
Cerisent's XQE
Cognetic Systems's XQuantum Enosys Software's XQuery Demo : http://xquerydemo.enosyssoftware.com
E-XMLMedia's
XMLizer: http://www.e-xmlmedia.com/prod/xmlizer.htm
Repository: http://www.e-xmlmedia.com/prod/repository.htm
Fatdog's XQEngine: http://www.fatdog.com/
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GAEL's Derby
GNU's Qexo (Kawa-Query)
Compiles XQuery on-the-fly to Java bytecodes. Based on and part of the Kawa framework. An online sandbox is available too. Open-source.
Ipedo's XML Database v3.0
Ispras Modis' Sedna. Open-source.
IPSI's IPSI-XQ
Fernandez/Simeon's Galax. Open-source, with a Galatex full text search implementation.
Mark Logic's Content Interaction Server. There is also a technical overview document. Commercial, with free download restricted to 50MBytes of data.
Microsoft's SQL Server 2005 Express, with XQuery support
Neocore's XML management system (XMS): http://www.neocore.com/products/products.htm Nimble Technology's Nimble Integration Suite: http://www.nimble.com/
--
OpenLink Software's Virtuoso Universal Server
Oracle's Xquery Technology - Preview
Politecnico di Milano's XQBE
QuiLogic's SQL/XML-IMDB
Renmin University of China's OrientX
Saxonica's Saxon. Available in a schema-aware version as a commercial product, and without schema support as open source.
Software AG's
Sonic Software's
Stylus Studio 5.0 (XQuery, XML Schema and XSLT IDE)
Sourceforge's eXist. Open-source.
Sourceforge's XQEngine. Open-source.
Sourceforge's XQuench. Open-source.
Sourceforge's XQuery Lite. See also documentation and description. PHP implementation, open-source.
Worcester Polytechnic Institute's RainbowCore. Java.
Xavier C. Franc's Qizx/Open. Java, open-source.
X-Hive's XQuery demo
XML Global's GoXML DB
Xpriori's NeoCore XMS native XML database, with XPath2.0/XQuery access language support. Free unlimited download for development purposes.
XQuark Group and Universite' de Versailles Saint-Quentin's: XQuark Fusion and XQuark Bridge, open-source (see also the XQuark home page)
