Summary: Mapserver <=> ArcIMS comparison

[Matt.Wilkie]

A few weeks ago asked mapserver-users, esri-l, comp.infosystems.gis,
and comp.soft-sys.gis.esri for comparitive comments on Mapserver
and ArcIMS. (respectively http://mapserver.gis.umn.edu/, 
http://www.esri.com/arcims/). Full text of all respondants is 
available on request.

Thank you to:
	Andrea Goethals, University of Florida
	John Hockaday, Department of Environment, Australia
	Michael Kleih, Centro Comune di Ricerca-JRC
	Michael Anderson, Spatial Information Technologies, Inc.
	Chris Stuber, Silicon Mapping Solutions, Inc

Mapserver-users (MSU) responses were detailed and informative, while 
the other three forums responded with a resounding silence. 

MSU unanimously acclaims Mapserver as the better web-based gis map
server, however it was pointed out the problem domains of Mapserver
and ArcIMS overlap while ArcIMS has a broader functionality set. In
the words of Micheal Anderson:

    "...I would like to point out that the scope of what ArcIMS and 
    MapServer attempt to do is different. ArcIMS has several 
    components designed to do things that MapServer alone doesn't 
    address. This includes html and applet based viewers for the client 
    as well as several components on the server. The components on the 
    server include the application server, manager components, and the 
    spatial servers. The spatial server is what renders the images, 
    handles spatial queries, extracts features, etc. The manager 
    components allow you to build "Map Services" (map files), create 
    web sites using the map services, and publish the sites.  The 
    application server allows you to distribute pieces of your 
    application over multiple machines and pool several machines to 
    handle increased loads.  It also allows you to use COM and Cold 
    Fusion in your application as the "connector" between the web server 
    and application server. ArcIMS has two additional components that 
    start and stop processes and delete images on a schedule.

    MapServer alone is only analogous to the spatial server, but the 
    other features can be added using other tools. Other than being 
    able to use fewer data formats, MapServer is a better spatial server 
    than ArcIMS's. By using an existing web application server you can 
    get the additional functionality with a minimal amount of work."

After several attempts, I can't reduce the length of Micheal's message
with out losing good info, so here is the rest of it:

    "...By using an existing web application server you can get the 
    additional functionality with a minimal amount of work. I am using
    Zope, which is Python based, as my application server. It is also 
    Open Source. It is a much better application server than the ArcIMS 
    component. In addition to allowing you to distribute your 
    application, and pool machines, it also handles user authentication, 
    and gives Unix like permissions to files, URLs, and operations. It 
    also handles publishing the sites easily. I haven't gotten around to
    using it to make the map files or the web site though. I use ArcView 
    to make the map files and have someone else make the web site. Zope 
    does allow me to share single html and JavaScript files across 
    multiple web sites, which makes maintenance a lot easier. It is also 
    possible to use Zope as a connector to ArcIMS so a single 
    application could use both MapServer and ArcIMS (as well as other 
    GIS engines). I am also aware of a Java based application server 
    called Enhydra that is also Open Source. I have installed it, but 
    haven't had much time to use it, so I can't really say what it can 
    do. There are also commercial application servers available like 
    IBM's WebSphere. You could probably do a lot with Cold Fusion as 
    well.
    
    "That said, here is my 2 cents on the advantages and disadvantages 
    of ArcIMS:

   "Advantages of ArcIMS
    - distribute applications over multiple machines
    - Native integration with the Geography Network. MapServer can be
      made to work within the geography network.
    - Includes software to handle routine tasks like making the map 
      services (map files), designing web sites, etc.
    - Supports more data formats - especially raster
    - Better support for storing spatial data in RDBMS through SDE
    - You don't have to try to sell a relatively unknown product 
      (MapServer) and philosophy (Open Source)

   "Disadvantages of ArcIMS
    - speed (even running mapserv as regular cgi it is much faster)
    - resource hog
    - limited OS (no Linux)
    - less stable. My ArcIMS experience is on NT so that may be more a
      reflection of the OS than ArcIMS.
    - poorer support
    - source code unavailable
    - cost"


All respondants felt Mapserver's support (via the user community) and
documentation is much more useful than ArcIMS'. It was noted that
often questions re:ArcIMS went completely unanswered. A couple of 
people made the point that although Mapserver's documentation is
better there are still some gaping holes; it is expected the newly 
formed documentation committee and mailing list will help address
this issue.

Several said Mapserver is easier to install and the maps are easier 
to maintain.

Most everybody said that Mapserver is faster* although theoretically
this should not be the case since Mapserver is a CGI while ArcIMS
is a Java app. (*nobody claimed ArcIMS is faster, just not everybody
made a speed comparison)

Those that made reliabilty comparisons felt that ArcIMS is still
buggy and undependable.

The one* plus ArcIMS seems to have over Mapserver is the GUI that 
allows development of the interface and equivalent to map files.
There is an ArcView extension and an Arc AML which make producing
Mapserver map files easier but they are still in development. There
is also talk of developing a standalone map builder but I'm not
sure how far along that project is yet.
(*where the problem domains overlap)

There were incidental threads comparing Mapserver to MapXtreme, and
JShape where Mapserver also came out on top.


Thanks to everybody who responded and a note to those who didn't:
I'm quite willing to do this again. I'm disappointed nobody came to
bat for ArcIMS. I was hoping to be able to summarize a broader range 
of opinions. Than again, maybe it is simply true that Mapserver
is better than ArcIMS. ;-)

cheers,

-matt
========================================
Matt Wilkie * GIS Technician * Yukon Renewable Resources GIS
http://renres.gov.yk.ca/pubs/rrgis/