XML Protocol

The XML Protocol ("XMLP") is a standard being developed by the W3C XML Protocol Working Group to the following guidelines, outlined in the group's charter:

  1. An envelope for encapsulating XML data to be transferred in an interoperable manner that allows for distributed extensibility.
  2. A convention for the content of the envelope when used for RPC (Remote Procedure Call) applications. The protocol aspects of this should be coordinated closely with the IETF and make an effort to leverage any work they are doing, see below for details.
  3. A mechanism for serializing data representing non-syntactic data models such as object graphs and directed labeled graphs, based on the data types of XML Schema.
  4. A mechanism for using HTTP transport in the context of an XML Protocol. This does not mean that HTTP is the only transport mechanism that can be used for the technologies developed, nor that support for HTTP transport is mandatory. This component merely addresses the fact that HTTP transport is expected to be widely used, and so should be addressed by this Working Group. There will be coordination with the Internet Engineering Task Force (IETF). (See Blocks Extensible Exchange Protocol)

Further, the protocol developed must meet the following requirements, as per the working group's charter:

  1. The envelope and the serialization mechanisms developed by the Working Group may not preclude any programming model nor assume any particular mode of communication between peers.
  2. Focus must be put on simplicity and modularity and must support the kind of extensibility actually seen on the Web. In particular, it must support distributed extensibility where the communicating parties do not have a priori knowledge of each other.

See also

External links

Computer-supported telecommunications applications

Computer-supported telecommunications applications (CSTA) is an abstraction layer for telecommunications applications. It is independent of underlying protocols. It has a telephone device model that enables CTI applications to work with a wide range of telephone devices. Originally developed in 1992, it has continued to be developed and refined over the years. It is often the model that most CTI applications are built on and claim compliance with. It became an OSI standard in July 2000. It is currently being maintained by ECMA International.

The core of CSTA is a normalized Call Control model. Additional to the core there are Call Associated features and Physical Device features amongst others. An implementation of the standard need not provide all features, and so Profiles are provided. For example, the Basic Telephony profile provides such features as Make Call, Answer and Clear Connection.


Eluta.ca is a job search engine that specializes in locating jobs in Canada. The Toronto-based search engine was launched on June 8, 2006 by the principals of Mediacorp Canada Inc., a specialty Canadian publisher of employment periodicals. Eluta.ca lets people find new job announcements by searching tens of thousands of employer websites across Canada.

Eluta aims to make every new job announcement in Canada searchable at no cost to the employer or job-seeker. To do this, Eluta.ca uses a variety of indexing and mathematical techniques to monitor vacancies at over 71,000 employers across Canada. One reviewer recently called the site the "Google for jobs". Unlike large job boards, no person determines the order of search results on Eluta, which are listed by relevance.The vertical search engine indexes only primary sources (no job boards or agency jobs are listed). As well, Eluta.ca includes employer reviews and other editorial information for job-seekers in its search results. These reviews are licensed from Mediacorp's line of employment periodicals, including Canada's Top 100 Employers. The Toronto Star recently described Eluta.ca as a "sea change" for job-searchers, stating that the site's attraction is its "simplicity and power".Like a growing number of search engines, Eluta has an open application programming interface, which lets programmers and website developers incorporate its data into other web applications. The API complies with the new OpenSearch XML protocol, an emerging standard that allows search engines to share their results in a standard and accessible format. Several websites have already created mashups using Eluta's data.

File format

A file format is a standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary or free and may be either unpublished or open.

Some file formats are designed for very particular types of data: PNG files, for example, store bitmapped images using lossless data compression. Other file formats, however, are designed for storage of several different types of data: the Ogg format can act as a container for different types of multimedia including any combination of audio and video, with or without text (such as subtitles), and metadata. A text file can contain any stream of characters, including possible control characters, and is encoded in one of various character encoding schemes. Some file formats, such as HTML, scalable vector graphics, and the source code of computer software are text files with defined syntaxes that allow them to be used for specific purposes.

Head–body pattern

The head–body pattern is a common XML design pattern, used for example in the SOAP protocol. This pattern is useful when a message, or parcel of data, requires considerable metadata. While mixing the meta-data with the data could be done it makes the whole confusing. In this pattern the meta-data or meta-information are structured as the header, sometimes known as the envelope. The ordinary data or information are structured as the body, sometimes known as the payload. XML is employed for both head and body (see also XML Protocol).

Henrik Frystyk Nielsen

Henrik Frystyk Nielsen (born 1969) is a Danish engineer and computer scientist. He is best known for his pioneering work on the World Wide Web and subsequent work on computer network protocols.

IRIS (transportation software)

IRIS (Intelligent Roadway Information System) is an open-source Advanced Traffic Management System (ATMS) software project developed by the Minnesota Department of Transportation. It is used by transportation agencies to monitor and manage interstate and highway traffic. IRIS uses the GPL license.


JourneyWeb is an XML protocol to allow distributed journey planning engines to communicate in order to provide multimodal journeys spanning different regions.

The protocol is a UK national de facto standard sponsored by the UK Department for Transport. It is used in the Transport Direct Portal.

JourneyWeb makes use of uniform UK Stop Data from NaPTAN

Local search (Internet)

Local search is the use of specialized Internet search engines that allow users to submit geographically constrained searches against a structured database of local business listings. Typical local search queries include not only information about "what" the site visitor is searching for (such as keywords, a business category, or the name of a consumer product) but also "where" information, such as a street address, city name, postal code, or geographic coordinates like latitude and longitude. Examples of local searches include "Hong Kong hotels", "Manhattan restaurants", and "Dublin car rental". Local searches exhibit explicit or implicit local intent. A search that includes a location modifier, such as "Bellevue, WA" or "14th arrondissement", is an explicit local search. A search that references a product or service that is typically consumed locally, such as "restaurant" or "nail salon", is an implicit local search.

Local searches typically trigger Google to return organic results and a local 3-pack. More local results can be obtained by clicking on “more places” under the 3-pack. The list of results one obtains is also called the Local Finder.Search engines and directories are primarily supported by advertising from businesses that wish to be prominently featured when users search for specific products and services in specific locations. Google for instance, has developed local inventory ads and features ads in the local pack. Local search advertising can be highly effective because it allows ads to be targeted very precisely to the search terms and location provided by the user.

PHP/Java Bridge

The original implementation of PHP has a PHP/Java Bridge separately available from SourceForge. This uses a dual process model where the Java libraries are run in a separate process from the PHP runtime. Interactions with Java objects are marshalled across to the Java process using an XML protocol.

Two other implementations, Quercus and Project Zero, implement PHP on top of the Java Virtual Machine and so can run the Java libraries in the same process as the PHP runtime. This reduces the overhead of interacting with Java libraries when compared with the dual process model of the original implementation.

Protocol Buffers

Protocol Buffers (Protobuf) is a method of serializing structured data.

It is useful in developing programs to communicate with each other over a wire or for storing data. The method involves an interface description language that describes the structure of some data and a program that generates source code from that description for generating or parsing a stream of bytes that represents the structured data.

Google developed Protocol Buffers for use internally and has provided a code generator for multiple languages under an open source license (see below).

The design goals for Protocol Buffers emphasized simplicity and performance. In particular, it was designed to be smaller and faster than XML.Protocol Buffers are widely used at Google for storing and interchanging all kinds of structured information. The method serves as a basis for a custom remote procedure call (RPC) system that is used for nearly all inter-machine communication at Google.Protocol Buffers are similar to the Apache Thrift (used by Facebook) or Microsoft Bond protocols, offering as well a concrete RPC protocol stack to use for defined services called gRPC.A software developer defines data structures (called messages) and services in a proto definition file (.proto) and compiles it with protoc. This compilation generates code that can be invoked by a sender or recipient of these data structures. For example, example.proto will produce example.pb.cc and example.pb.h, which will define C++ classes for each message and service that example.proto defines.

Canonically, messages are serialized into a binary wire format which is compact, forward- and backward-compatible, but not self-describing (that is, there is no way to tell the names, meaning, or full datatypes of fields without an external specification). There is no defined way to include or refer to such an external specification (schema) within a Protocol Buffers file. The officially supported implementation includes an ASCII serialization format, but this format—though self-describing—loses the forward- and backward-compatibility behavior, and is thus not a good choice for applications other than debugging.

Though the primary purpose of Protocol Buffers is to facilitate network communication, its simplicity and speed make Protocol Buffers an alternative to data-centric C++ classes and structs, especially where interoperability with other languages or systems might be needed in the future.


SOAP (abbreviation for Simple Object Access Protocol) is a messaging protocol specification for exchanging structured information in the implementation of web services in computer networks. Its purpose is to provide extensibility, neutrality and independence. It uses XML Information Set for its message format, and relies on application layer protocols, most often Hypertext Transfer Protocol (HTTP) or Simple Mail Transfer Protocol (SMTP), for message negotiation and transmission.

SOAP allows processes running on disparate operating systems (such as Windows and Linux) to communicate using Extensible Markup Language (XML). Since Web protocols like HTTP are installed and running on all operating systems, SOAP allows clients to invoke web services and receive responses independent of language and platforms.

Service Interface for Real Time Information

The Service Interface for Real Time Information or SIRI is an XML protocol to allow distributed computers to exchange real time information about public transport services and vehicles.

The protocol is a CEN norm, developed originally as a technical standard with initial participation by France, Germany (Verband Deutscher Verkehrsunternehmen), Scandinavia, and the UK (RTIG)

SIRI is based on the CEN Transmodel abstract model for public transport information, and comprises a general purpose model, and an XML schema for public transport information.

A SIRI White Paper is available for further information on the protocol.


The Sitemaps protocol allows a webmaster to inform search engines about URLs on a website that are available for crawling. A Sitemap is an XML file that lists the URLs for a site. It allows webmasters to include additional information about each URL: when it was last updated, how often it changes, and how important it is in relation to other URLs in the site. This allows search engines to crawl the site more efficiently and to find URLs that may be isolated from rest of the site's content. The sitemaps protocol is a URL inclusion protocol and complements robots.txt, a URL exclusion protocol.

Web Services Description Language

The Web Services Description Language (WSDL ) is an XML-based interface description language that is used for describing the functionality offered by a web service. The acronym is also used for any specific WSDL description of a web service (also referred to as a WSDL file), which provides a machine-readable description of how the service can be called, what parameters it expects, and what data structures it returns. Therefore, its purpose is roughly similar to that of a type signature in a programming language.

The current version of WSDL is WSDL 2.0. The meaning of the acronym has changed from version 1.1 where the "D" stood for "Definition".


XCB (X protocol C-language Binding) is a library implementing the client-side of the X11 display server protocol. XCB is written in the C programming language and distributed under the MIT License. The project was started in 2001 by Bart Massey and aims to replace Xlib.


Extensible Markup Language (XML) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. The W3C's XML 1.0 Specification and several other related specifications—all of them free open standards—define XML.The design goals of XML emphasize simplicity, generality, and usability across the Internet. It is a textual data format with strong support via Unicode for different human languages. Although the design of XML focuses on documents, the language is widely used for the representation of arbitrary data structures such as those used in web services.

Several schema systems exist to aid in the definition of XML-based languages, while programmers have developed many application programming interfaces (APIs) to aid the processing of XML data.

XML log

XML log or XML logging is used by many computer programs to log the programs operations. An XML logfile records a description of the operations done by a program during its session. The log normally includes: timestamp, the programs settings during the operation, what was completed during the session, the files or directories used and any errors that may have occurred. In computing, a logfile records either events that occur in an operating system or other software running. It may also log messages between different users of a communication software. XML file standard is controlled by the World Wide Web Consortium as the XML file standard is used for many other data standards, see List of XML markup languages. XML is short for eXtensible Markup Language file.

X Window System protocols and architecture

In computing, the X Window System (commonly: X11, or X) is a network-transparent windowing system for bitmap displays. This article details the protocols and technical structure of X11.

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