The following comments are aimed at clarifying the reasons for choosing one of the various solutions for web-based interactive cartography. This is a hot topic at the moment, which is a good sign for service providers. But the competition is tough between the would-be most standard, most legitimate, most professional, least expensive, most compatible, freest, least American standard

Technically, there are two ways to provide web-based interactive cartography:

As bitmap images produced on-the-fly by a server sepcialising in geographic processing. The browser displays Gif or Jpeg images that include sensitive areas.

As images drawn by the browser through specific interpreters (DirectX for the PC version of Internet Explorer), the Java virtual machine when installed, additional client programmes (plugins) of varying sizes and levels of cartographic specialisation, or finally standard integrated Svg interpretation. If the browser is able to send vectorial data to a printer port (including Acrobat Distiller), the images are called vectorial images, which guarantees high-quality exports or printouts, if not, they are simply bitmap images drawn on demand by the browser. Let us take an example at random: Flash player outputs are vectorial, while the Adobe Svg player's are bitmap. In fact, an image is always converted to bitmap when it is displayed or printed, but it should loose its vectorial source as late as possible.

The first technique is the most reliable. It guarantees that the web-base cartography application will be viewable immediately by all browsers, except those that cannot read Gif or Jpeg files (if such browsers even exist). It also offers the least viewing quality, printing quality, display speed for large sizes and interactivity. Strangely, it is nevertheless the most expensive! It is offered by all major GIS editors, through the installation of a specific application on the Internet server. Of course, you must either have a strong host server on which you can install your own software, or rely on a hosting provider specialising in cartography servers.

The second technique, which transfers part of the processing tasks to the client workstation, is therefore widely used. It is also - relatively - new, and the subject of many more or less deliberate, amusing and recurrent myths or untruths. First, it pits the specialised technology of major GIS editors (Esri, Mapinfo, Autodesk, etc.) against general-purpose vectorial formats (Flash, Svg). Second, it sparks lively debates between flashers and svgists.
Since it relies on a client browser, an entity that is by definition less uniform and controllable than a server, it must abide by three simple rules if it is to reach a wide audience:

 Guaranteed compatibility of the viewing technique (plugin, Java) with all browsers, or rather knowledge of the present state of compatibility and future involvement of concerned editors. Well-placed contestants include major GIS editors, who have been developing and distributing such plugins for over 3 years, and Macromedia, who reached this priority objective on all counts with the release of version 6 for Linux at the end of 2002. As for Svg, Corel was the most dynamic player in late 2002 and early 2003, with the release of a player and a development tool. The Svg developer community is waiting impatiently for Adobe's reaction and especially version 6 of its player, probably in early 2004 (a pre-alpha version is currently available for download).

A reasonnable plugin size (under 1Mb, at worst). Weighing in at 400Kb, Flash leads the way while other plugins are seldom smaller than 2Mb. Java solutions use the virtual machine of the same name, which is not always included with the browser and represents over 10Mb. In addition, Java applications are not always stable, to say the least, and the entire application must be reloaded each time it is used. On the other hand, once installed, plugins support many basic functions once and for all. As for the integration of vectorial features in browsers, Svg is the standard recommended by W3C but Microsoft continues to favour VML and has no plans to change. Mozilla was to include standard Svg playing. But this goal has not yet been reached and its market share remains limited. If Microsoft finally includes Svg, it will not be before at least 2 years, i.e. 3 or 4 years before the new browser version spreads sufficiently.

A widely distributed plugin. Here are the results from a quarterly survey organised by an independent institute:

Image viewing plugin statistics (United States):

Source: NPD - Médiametrix, June 2003
Methodology: quarterly survey of 2,000 people who tested on-screen whether they saw the same content in each of the above formats.
In June 2003, 87% of European Internet users had Flash version 6 on their computer.