Maps for HTML Community Group

🔗 About the Community Group

The Maps for HTML Community Group is working to standardize methods of defining interactive geographic maps for the web.

The community group is hosted by the W3C (World Wide Web Consortium), and is open to anyone who is interested in maps and web standards.

For more information, consult:

• Maps for HTML Community Group homepage on w3.org

  Includes a blog, lists of current participants and chairs , along with other information (most of which is also available here) such as links to the group's draft reports and social media.

  Most importantly of all, this is where you join the Maps for HTML Community Group!

  To join the community group you'll need to create a W3C account , and accept the W3C Community Contributor License Agreement. If you have an employer with rights to work you create, they may need to join on your behalf.

• “About” page for all W3C-hosted community groups

  With details on the process and legal/intellectual property requirements for community group participation, and especially our Code of Conduct.

• The group mailing list archive

  Contains a history of notices and discussion. However, most discussion happens within the GitHub project repositories.

• Maps4HTML organization on GitHub

  Most work by the group can be found here (including this web page).

🔗 Specifications and Reports

The group's reports and explainers:

• Report on the Joint W3C-OGC Workshop on Maps for the Web

  The report on the Web mapping workshop that was held by the W3C and OGC.

• Use Cases and Requirements for Standardizing Web Maps (GitHub repository)

  An overview of why HTML needs a built-in map viewer element, which can combine multiple layers into an interactive view.

• MapML proposal

  An explainer of the MapML proposal. This may be the best place to start in trying to understand the substance of the MapML proposal.

• MapML specification (GitHub repository)

  Map Markup Language (MapML) is a proposal for a new document format for describing maps, which could contain a mix of tiled images, vector features (e.g., points, lines, polygons), and hyperlinks to related resources.

  Includes a proposal for how the HTML map viewer and layer elements could be defined. MapML documents could be used as layers in an HTML map viewer.

• MapML UCR Fulfillment Matrix (GitHub repository)

  Hosted examples and documents how MapML and existing popular web mapping libraries fulfill the Use Cases and Requirements for Standardizing Web Maps.

• MapML Engineering Reports from the OGC Innovation Program
  • Testbed 13 - early community ideas
  • Testbed 14 - improved vocabulary
  • Testbed 15 - improved vector model
  • Testbed 16 - Review of MapML proposal by Simon Pieters
• The Design of MapML

  A blog post detailing how the MapML proposal relates to the HTML Design Principles.

🔗 Software projects

The following projects (hosted by the community group's GitHub account) make it possible to experiment with the proposed specifications:

• MapML implemented as custom elements

  A polyfill of the MapML proposal, as a set of HTML custom elements, using Leaflet as the map rendering engine.

  See hosted experiments and documentation for the MapML-viewer polyfill.

• MapML Browser extension

  Chromium browsers only (Manifest v3). Among other functions, the browser extension renders remote MapML documents as maps, that would be otherwise unintelligible to the browser without a host Web page containing the custom elements that implement the vocabulary.

  Implements map internationalization / localization.

• GeoServer MapML Extension

  A GeoServer extension that enables MapML output, supporting images, features and tiles. There is basic documentation available on how to install the module.

• MapServer MapML module

  The MapServer project is one of the earliest and most mature implementations of the OGC WMS specification. The MapServer implementation of MapML is scheduled for release with MapServer 8.2. Currently looking for a volunteer to shepherd the project to production.

• HTML-MapML Validator

  An experimental / work in progress fork of the validator.nu project which validates MapML documents. The objective is to validate HTML including map markup as well as independent text/mapml documents.

• HTML-MapML Parser

  An experimental / work in progress fork of the validator.nu HTML parser.

• pygeoapi MapML Formatter Plugin

  MapML Formatter Plugin for pygeoapi.

• MapMLServer

  MapML tile servlet Maven Java project.

🔗 Working Demos

Websites that use the custom element and MapML server, hosted by Natural Resources Canada.

• Demo MapML services

  Interactive map viewers, with maps on various subjects and in various projections, including arctic views (not supported by most web map tiling systems).

• Vector example

  This document uses the prototype GeoJSON API to transform GeoJSON content into styled MapML vectors.

🔗 Related standards and document formats

The following standards may be of relevance to maps in HTML:

• OGC Standards and Supporting Documents

  The Open Geospatial Consortium (OGC) publishes standards for map-related data, some of which are used or adapted by MapML:

  • Web Map Service
  • Web Map Tile Service
  • Tile Matrix Set
  • Simple Features
• GeoJSON specification

  IETF standard RFC 7946 is a standardized representation of vector feature data in JSON structure.

• Geo URI specification

  IETF RFC 5870 is a URI scheme allowing WGS 84 locations to be conveyed in URLs conforming to a specified URI scheme.

• Pan and Zoom CSSWG proposal

  A proposed CSS primitive for per-element panning and zooming.

• Spatial Data on the Web Best Practices and Use Cases and Requirements

  These reports were prepared by the Spatial Data on the Web Working Group (now Interest Group), a joint project of the OGC and W3C. Some of the recommendations are relevant to map viewers and map data servers.

• The Responsible Use of Spatial Data

  A report on responsible use of Spatial Data on the web by the Spatial Data on the Web Interest Group.

🔗 Events

Conferences, meeting minutes, presentations, workshops, and other notable events:

1. Maps for HTML Community Group meeting - TPAC 2022 Hybrid meeting minutes September 15, 2022
2. Maps for HTML Community Group meeting - TPAC 2022 Hybrid meeting minutes September 12, 2022
3. Maps for HTML Community Report meeting minutes and presentation SDWIG teleconference. 24 June, 2021.
4. Summary presentation of the W3C/OGC Joint Workshop Series on Maps for the Web and follow-up discussion W3C TPAC, virtual meeting. 27 October, 2020.
5. W3C/OGC Joint Workshop Series on Maps for the Web W3C/OGC virtual workshop, hosted by NRCAN. September 2–October 21, 2020.
6. Native maps in the browser (and HTML) submission and presentation WebWeWant event, Smashing conference. New York, NY USA. October 15–16, 2019.
7. MapML: The (new) map HTML element, now in MapServer, GDAL and OGR agenda and presentation FOSS4G. Bucharest, Romania. August 28, 2019.
8. Integrate Web map support into browsers agenda and meeting minutes W3C TPAC. Fukuoka, Japan. September 16–20, 2019.
9. What can bring MapML to the INSPIRE community submission and presentation INSPIRE conference. Antwerp, Belgium. September 19, 2018.
10. MapML discussion: meeting minutes SDWIG F2F/IRC. Amersfoort, Netherlands. February 20, 2018.
11. Extending the Web with Maps presentation Location and the Web workshop. Montreal, Canada. April 11–15, 2016.
12. GeoGratis API reference and BarCamp notes – extending the web to enable linked geospatial data (birth of the Maps for HTML Community Group!) W3C/OGC Linking Geospatial Data workshop. London, England. March 6, 2014.

🔗 Other links

The following related projects aren't controlled or published by the community group, but may be of interest:

• Open source JavaScript libraries for building custom Web maps:
  • OpenLayers
  • Leaflet
• SVGMap

  An alternative to MapML for standardizing interactive web maps, building on the ability of SVG to mix image tiles with vector features and hyperlinks.

  See the related proposals for standardizing key new SVG features: SVG Tiling and Layering Module (proposal) and SVG globalView proposal.