A is for Acronym Libraries and Internet Standards

A is for Acronym: Libraries and Internet Standards for Serialists Shelley Neville Howard Rosenbaum http: //www. slis. indiana. edu/hrosenba/www/Pres/nasig_02/

I. Introduction: Internet standards and the standards setting process II. Technical standards: • Internet communications standards • Architectural standards III. Metadata standards IV. Applications standards • Basic markup languages • Basic programming languages • Extensible markup language

I. Introduction: Internet standards and the standards setting process Private Sector IAB IRTF IESG

1. Internet standards and the standards setting process 2. How are Internet standards set? 3. Formal standards setting 4. Organizations use bureaucratic procedures for creating and approving standards 5. Members can be drawn from government, business, researchers and users 6. They meet regularly to discuss proposed standards 7. Standards are set through voting or consensus building

Internet standards and the standards setting process Organizations setting Internet standards range from formal to volunteer ICANN: Internet Committee for Assigned Names and Numbers An international formal organization with elected representatives It is a “private-sector body responsible for coordinating the global Internet's systems of unique identifiers” http: //www. icann. org/

Internet standards and the standards setting process ICANN’s mission is to coordinate the stable operation of the Internet’s unique identifier systems by Coordinating the allocation and assignment of three sets of unique identifiers: Domain names (forming the DNS system) Internet protocol (IP) addresses, autonomous system (AS) numbers, protocol port and parameter numbers Coordinates the operation and evolution of the DNS's root name server system

Internet standards and the standards setting process Internet Society (ISOC) Non-profit, NGO, international, professional membership organization Mission is to develop standards, provide education, and address Internet policy issues 150 local organizations and 8, 600 members in 170 nations Home to groups responsible for Internet standards, including IETF and the IAB http: //www. isoc. org

Internet standards and the standards setting process Internet Engineering Steering Group (IESG) Responsible for technical management of IETF activities and the Internet standards process Administers the process according to rules and procedures ratified by the ISOC Trustees Ratifies or corrects the output from IETF's Working Groups Gets WGs started and finished Makes sure that non-WG drafts that are about to become RFCs are correct http: //www. ietf. org/iesg. html

Internet standards and the standards setting process Internet Architecture Board (IAB) Created in 1984 by Vint Cerf Advises ISOC on technical matters Provides oversight of technical standards setting process Manages RFC series http: //www. iab. org Internet Research Task Force (IRTF) Working groups investigate topics related to Internet protocols, applications, architecture and technology http: //www. irtf. org

Internet standards and the standards setting process Internet Engineering Task Force (IETF) Formed in 1986 A large open international community of network designers, operators, vendors, and researchers that is open to any interested individual Concerned with the evolution of the Internet architecture and the smooth operation of the Internet Members work to resolve technical problems and on the development of new Internet standards This is where the basic work gets done http: //www. ietf. org/

Internet standards and the standards setting process Internet Assigned Names Authority (IANA) Chartered by ISOC to act as the clearinghouse for assigning and coordinating the use of Internet protocol parameters “Dedicated to preserving the central coordinating functions of the global Internet for the public good” Conducts research on domain name system issues Works with ICANN to maintain the DNS The central coordinator for the assignment of unique parameter values for Internet protocols http: //www. iana. org

Internet standards and the standards setting process World Wide Web Consortium (W 3 C) Created in October 1994 Goal is to develop common protocols that promote the evolution of the web and ensure its interoperability Has more than 400 member organizations Financed by members and some public funds Assigns defined groups of experts to solve specific tasks Produces specifications likely to meet the needs of its members and the community http: //www. w 3. org

Internet standards and the standards setting process Standards are also set in an ad-hoc fashion This occurs in the marketplace Vendors compete to have their proprietary standards adopted This leads to situations where the best standards does not always win The browser “wars” of the early 90 s were a good example Voice-over-IP is another example

I. Introduction: Internet standards and the standards setting process II. Technical standards: • Internet communications standards • Architectural standards III. Metadata standards IV. Applications standards • Basic markup languages • Basic programming languages • Extensible markup language

II. Technical standards: Internet communications standards Transmission Control Protocol/Internet Protocol (TCP/IP) Allows computers to share resources across a network Services: routing, message delivery, FTP, Remote login, email Hypertext transfer protocol (HTTP) Allows the transfer of hypertext among computers across a network Overlaid onto TCP/IP Uses client/server “stateless” connections Links to other TCP/IP protocols

Technical standards: Internet communications standards Internet Protocol, version 6 (IPv 6) A new version of the basic addressing protocol Expands IP address size from 32 -128 bits Allows packet encryption Wireless Application Protocol (WAP) XML-based markup language for digital mobile devices Received on microbrowsers It is an open specification and can be used by any vendor It uses a variation of the client-server model adding “push”

Technical standards: Internet communications standards Institute of Electrical and Electronics Engineers 801. 11 b (IEEE 801. 11 b) Allows local wireless networking with a throughput rate of 11 Mbps) Wireless Ethernet Compatibility Alliance (WECA) Certification (Wi-Fi) Certifies that a product can operate across wireless platforms and communicate with other vendor’s products Bluetooth A wireless protocol and hardware allowing digital devices to exchange data within a 30’ range

Technical standards: Internet communications standards Z 39. 50 American National Standard Information (ANSI) Retrieval Application Service Definition and Protocol Specification for Open Systems Interconnection Defines standard procedures and features for computers to communicate for information search and retrieval Enables different computer systems to interoperate and work together seamlessly They can have different operating systems, hardware, search engines, database management systems

Technical standards: Internet communications standards Top level domains (TLDs) These are the highest level internet addresses that provide the initial hierarchy They represent the root of the numerical IP address Common TLDs: . edu, . com. , . org, . net, . gov, . mil Also country codes (. us, . de. . uk) New TLDs Sponsored: . aero, . coop, . museum Unsponsored: . biz, . info, . name, . pro

Technical standards: Architectural standards Document Object Model (DOM) Applications programming interface (API) for HTML/XML A scheme that orders objects that make up a web page Defines the logical structure of documents and the way a document is accessed and manipulated Provides a location for these objects window. document. form. checkbox Used in dynamic HTML (DHTML) Scripting languages use the DOM to locate the objects upon which they act

Technical standards: Architectural standards Simple Object Access Protocol (SOAP) Provides a way to access services, objects, and servers in a completely platform-independent manner Allows querying, invoking, and communicating with services provided on remote systems Written in and used with XML Contains a suite of functionalities Service Description Language (SDL) SOAP Contract Language (SCL) Discovery of Web Services (DISCO)

I. Introduction: Internet standards and the standards setting process II. Technical standards: • Internet communications standards • Architectural standards III. Metadata standards IV. Applications standards • Basic markup languages • Basic programming languages • Extensible markup language

III. Metadata standards W 3 C’s Resource Description Format (RDF) is a generic metadata architecture A standard supporting the definition of metadata across the web Describes how metadata for content is defined in web documents This metadata is descriptive information about the structure and content of information in a document Useful for describing information about indexing, navigating and searching, push channel definitions and digital signatures http: //www. w 3 c. org/RDF/

Metadata standards RDF is the instantiation of the Warwick Framework for the Web The basic RDF data model consists of three object types: Resource: anything that can be specified by a URI, such as a web page, an entire web site, a specific newsgroup message Properties: characteristics or attributes of a resource, along with some notion of meaning, valid values, etc. Statements: resource + named property + value of property

Metadata standards Using XML, it might look like this: <RDF xmlns: DC="http: //purl. org/DC"> <Description about="http: //www. w 3. org/folio. html"> <DC: Title>The W 3 C Folio 1999</DC: Title> <DC: Creator>W 3 C Communications Team</DC: Creator> <DC: Date>1999 -03 -10</DC: Date> <DC: Subject>Web development, World Wide Web Consortium, Interoperability of the Web</DC: Subject> </Description> </RDF>

Metadata standards OCLC’s Persistent URL (PURL) Functionally, a PURL is a URL with three parts Protocol: this is used to access the PURL resolver This protocol may differ from that used to access the resource associated with the PURL Resolver address: the IP address or domain name of the PURL resolver Name: user-assigned name Note: This may differ from the name of the resource in the associated URL http: //www. oclc. org/purl

Metadata standards A PURL points to an intermediate resolution service, not the location of the Internet resource The PURL resolution service associates the PURL with the actual URL and returns the URL to the client The client can then complete the URL transaction in the normal fashion The advantage of PURLs is that they persist over time no matter where the page moves http: //purl. oclc. org/your. address/yourfile. html protocol resolver address filename

Metadata standards The model works something like this: C L I E N T PURL URL RESOURCE PURL SERVER RESOURCE SERVER

I. Introduction: Internet standards and the standards setting process II. Technical standards: • Internet communications standards • Architectural standards III. Metadata standards IV. Applications standards • Basic markup languages • Basic programming languages • Extensible markup language

IV. Applications standards: Basic markup languages Some relationships among markup languages SGML HTML XML eb. XML HTML 3. 2 XSLT MML CSS HTML 4. 01 CML XHTML

Applications standards: Basic markup languages Standard Generalized Markup Language (SGML) Metalanguage developed in 1974 by Charles Goldfarb Became ISO standard in 1986 (ISO 8879 - Information Processing -- Text and Office systems) Based on entities, elements, attributes, content models, and document types Describes the structure and content of machine readable information Facilitates exchange of complex structured data among systems http: //www. sgmlsource. com

Applications standards: Basic markup languages Hypertext Markup Language (HTML) A very rigid application of SGML for the web Developed through HTML 4. 01 Cascading Style Sheets (CSS) Provides flexibility missing in HTML Extensible Hypertext Markup language (XHTML) HTML rewritten as an XML application Follows the rules of XML http: //www. w 3. org/Markup/

Applications standards: Basic markup languages Here's a simple XHTML document: <html> <head> <title>Memo form</title> </head> <body> 4. 10. 01 TO: John Doe CC: Jane Doe FROM: Bozo T. Clown Please take note our phone number has changed. Yours in clownitude, Bozo </body> </html>

Applications standards: Basic programming languages Common Gateway Interface (CGI) A executable standard linking external applications with information servers (typically Web servers) Allows the generation of dynamic information Ex: linking a web form to a database Practical Extraction and Report Language (Perl) Programming language for processing text developed by Larry Wall It can scan text files, extract information, print reports based in the information

Applications standards: Basic programming languages Python An object oriented language that has many of the capabilities of Perl Javascript Netscape’s client-side scripting language Java Sun’s server-side programming language that allows programs to be downloaded from server to client and executed on the client PHP: Hypertext Preprocessor (PHP) Open source scripting language designed for web development

Applications standards: Basic programming languages CGI http: //hoohoo. ncsa. uiuc. edu/cgi/intro. html Perl http: //www. perl. org Python http: //www. python. org Javascript http: //developer. netscape. com/tech/javascript/index. html Java http: //java. sun. com/nav/what-is/ PHP http: //www. php. net

Applications standards: Extensible markup language Extensible Markup Language (XML) A meta-language based on SGML Extensible: authors can define their own tags and attributes CML: Chemical Markup Language Math. ML: Mathematical Markup Language eb. XML: Electronic Business Markup Language Properly done, XML documents can be viewed across platforms W 3 C Recommendation 2/10/98, corrected 10/6/00 http: //www. w 3. org/TR/REC-xml

Applications standards: Extensible markup language An XML document us actually composed of three different files The raw XML file (. xml) It must follow certain rules to be considered “well formed” and “valid” Document Type Definition (DTD) A set of rules that defines the elements, entities, attributes that can be used in. xml files Determines how they can be used and how they are logically related Elements in a DTD are hierarchical and nested

Applications standards: Extensible markup language This is the XML file <? xml version="1. 0" standalone="no"? > <!DOCTYPE MEMO SYSTEM "http: //www. site. com/dtds/memo. dtd"> <memo> <header type=“informative”> <date>04. 10. 01</date> <to> <name>John Doe</name> </to> <cc> <name> Jane Doe </name> </cc> <from> <sender>Bozo T. Clown</sender> </from> </header> <memotext> Please take note our phone number has changed. &sig; </memotext> </memo>

Applications standards: Extensible markup language This is the DTD for the XML file <!ENTITY sig “Yours in clownitude, Bozo”> <!ELEMENT memo (header, memotext)> <!ELEMENT header (date, to, cc? , from)> <!ATTLIST header type (informative | directive | scheduling)> <!ELEMENT date (#PCDATA)> <!ELEMENT to (name+)> <!ELEMENT name (#PCDATA)> <!ELEMENT cc (name*)> <!ELEMENT from (sender+) <!ELEMENT sender (#PCDATA)> <!ELEMENT memotext (#PCDATA)> + = must appear at least once or many times ? = may be omitted or can appear once * = may be omitted or can appear many times | = one or the other but only one may appear #PCDATA = text

Applications standards: Extensible markup language XML Schema are an alternative to DTDs Schemas allow global (the same everywhere) and local (differ in different contexts) elements All DTD elements are “global, ” so an element can only be defined once and in one way DTD elements cannot be used differently in different contexts Schemas can specify data types for elements - DTDs cannot Schemas are written in XML - DTDs are not http: //www. w 3 org/XML/Schema

Applications standards: Extensible markup language <? xml version=“ 1. 0”? > <xml: schema xmlns: xsd=“http: //www. w 3 c. org/2000/10/XMLSchema”> <xsd: element name=“name” type=“xsd: string”> <xsd: complex. Type name=“memo”> <xsd: sequence> <xsd: complex. Type=“header”> <xsd: element name=“date” type =“xsd: date”> This is a <xsd: complex. Type=“to”> schema <xsd: element ref=“name”/> </xsd: complex. Type> <xsd: complex. Type=“cc”> <xsd: element ref=“name”/> </xsd: complex. Type> <xsd: complex. Type=“from”> <xsd: element=“sender” type =“xsd: string”> </xsd: complex. Type> <xsd: element name=“memotext” type =“xsd: string”> </xsd sequence> <xsd: attribute name=“type” value=“informative | directive | scheduling”> </xsd: complextype> </xsd: schema>

Applications standards: Extensible markup language Extensible Stylesheet Transformation Language (XSLT) Transformation rules that determine how components of an XML file will be rendered and displayed in a range of formats (. xsl extension) The rules tell the processor what content to extract and how to format and display it A process can be specified to convert XML documents into other formats (HTML, RTF, La. Te. X, text) A. xsl file is also an XML document and must be “well formed” Uses Xpath, Xpointer, Xlink to provide “filepaths” for the processor to follow

Applications standards: Extensible markup language Here’s what the XSL stylesheet might look like <? xml version=“ 1. 0”> <xsl stylesheet xmlns=“http: //www. w 3. org/TR/WD-xsl” version=“ 1. 0”> <xsl template match=“/”> <html> <head> <title>Memo form</title> </head> <body> <xsl: template match=“header”> <xsl: apply-templates select=“date” /> TO: <xsl: apply-value-of select=“to/name” /> CC: <xsl: apply-value-of select=“cc/name” /> FROM: <xsl: apply-value-of select=“from/sender” /> </xsl: template> <xsl: apply value-of select=“memotext” /> <xsl: apply value-of select=“&sig; ” /> </body> </html> </xsl: template> </xsl: stylesheet>

Applications standards: Extensible markup language SGML/XML applications Encoded Archival Description (EAD) International standard based on SGML for describing the structure of an archival finding aid ISO/IEC 10744 Hypermedia/Time-Based Structuring Language (Hy. TIME) Defines the generic structure of hypermedia documents Standardized Multi. Media Integration Language (SMIL) Allows synchronization and positioning of digital audio and video on a web page

Applications standards: Extensible markup language SGML/XML applications Text Encoding Initiative (TEI) Guidelines for encoding machine-readable text Works with XML Electronic Business Markup Language (eb. XML) An XML application that represents business processes as structured information The motherlode of information is the “Cover pages” http: //www. oasis-open. org/cover/sgml-xml. html

Howard Rosenbaum hrosenba@indiana. edu http: //www. slis. indiana. edu/hrosenba/www/Pres/nasig_02/