A marker is a symbol which is attached to one or more vertices of ‘path’ , ‘line’ , ‘ polyline ’ and ‘polygon’ elements. Typically, markers are used to make arrowheads or polymarkers. Arrowheads can be defined by attaching a marker to the start or end vertices of ‘path’ , ‘line’ or ‘ polyline ’ elements. Polymarkers can be defined by attaching a marker to all vertices of a ‘path’ , ‘line’ , ‘ polyline ’ or ‘polygon’ element. The graphics for a marker are defined by a ‘marker’ element. To indicate that a particular ‘marker’ element should be rendered at the vertices of a particular ‘path’ , ‘line’ , ‘ polyline ’ or ‘polygon’ element, set one or more marker properties ( ‘marker’ , ‘marker-start’ , ‘marker-mid’ or ‘marker-end’ ) to reference the given ‘marker’ element.
Geo RSS (Really Simple Syndication) RSS can be leveraged to provide technology to create both highly structured and machine readable information. RSS allows users to subscribe to their favourite news streams or blogs RSS can be used to alert users to new postings Advantage of RSS is its ease of use and flexibility
GeoRSS is an emerging standard for encoding location as part of an Web feed . (Web feeds are used to describe feeds (&quot;channels&quot;) of content, such as news articles, Audio blogs , video blogs and text blog entries. These web feeds are rendered by programs such as aggregators and web browsers .) The name &quot;GeoRSS&quot; is derived from RSS , the most known Web feed and syndication format. In GeoRSS, location content consists of geographical points, lines, and polygons of interest and related feature descriptions. GeoRSS feeds are designed to be consumed by geographic software such as map generators. By building these encodings on a common information model, the GeoRSS collaboration is promoting interoperability and &quot;upwards-compatibility&quot; across encodings. At this point, the GeoRSS collaboration has completed work on two primary encodings that are called GeoRSS Geography Markup Language (GML) and GeoRSS Simple. GeoRSS-Simple is a very lightweight format that supports basic geometries (point, line, box, polygon) and covers the typical use cases when encoding locations. GeoRSS GML is a formal Open Geospatial Consortium (OGC) GML Application Profile, and supports a greater range of features than GeoRSS Simple, notably coordinate reference systems other than WGS84 latitude/longitude. There is also a W3C GeoRSS serialization, which is older and partly deprecated but still the most widely used. GeoRSS can be used to extend both RSS 1.0 and 2.0, as well as Atom , the IETF 's latest standard for feeds.
RSS (most commonly expanded as Really Simple Syndication ) is a family of web feed formats used to publish frequently updated works—such as blog entries, news headlines, audio, and video—in a standardized format.  An RSS document (which is called a &quot;feed&quot;, &quot;web feed&quot;,  or &quot;channel&quot;) includes full or summarized text, plus metadata such as publishing dates and authorship. Web feeds benefit publishers by letting them syndicate content automatically. They benefit readers who want to subscribe to timely updates from favored websites or to aggregate feeds from many sites into one place. RSS feeds can be read using software called an &quot;RSS reader&quot;, &quot;feed reader&quot;, or &quot; aggregator &quot;, which can be web-based , desktop-based , or mobile-device-based. A standardized XML file format allows the information to be published once and viewed by many different programs. The user subscribes to a feed by entering into the reader the feed's URI or by clicking an RSS icon in a web browser that initiates the subscription process. The RSS reader checks the user's subscribed feeds regularly for new work, downloads any updates that it finds, and provides a user interface to monitor and read the feeds. RSS formats are specified using XML , a generic specification for the creation of data formats. Although RSS formats have evolved from as early as March 1999,  it was between 2005 and 2006 when RSS gained widespread use, and the (&quot; &quot;) icon was decided upon by several major Web browsers. 
Mapping Services & The Web: Web 2.0 provides valuable opportunity to provide mapping & location services: Embedding Google maps on your Web sites Developing rich services using this Providing location metadata / microformats which can be processed by simple browser tools
Geography Markup Language 3.0 (GML) GML defines a data encoding in XML that allows geographic data and its attributes to be moved between disparate systems with ease Geography Markup Language (GML) is an XML grammar written in XML Schema for the modeling, transport, and storage of geographic information. GML provides a variety of kinds of objects for describing geography including features, coordinate reference systems, geometry, topology, time, units of measure and generalized values.
KML … • is a file format used to display geographic data in an Earth browser, such as Google Earth, Google Maps, and Google Maps for mobile. • it is based on the XML standard • it describes… Content + Map Symbols + View point + … A KML file can be created … • with the Google Earth user interface, or • from scratch …use an XML or simple text editor to enter &quot;raw&quot; KML KMZ… • KML files and their related images (if any) can be compressed using the ZIP format into KMZ archives
Web2.0 @ Web Mapping
Web 2.0 @ Mapping G. Sreedhar Research Scholar (PhD student @ IIT Bombay) Knowledge Management and Sharing ICRISAT
Web 2.0 @ Mapping Wiki Mapia Geo RSS Geo Markers Mash-ups Web 2.0 Embed : Photos, Videos and Description