opensource gis desktop clients

Recently some opensource (free) desktop GIS clients came to my attention.

• uDig (http://udig.refractions.net/confluence/display/UDIG/Home ) is a java-eclipse based environment for viewing maps (.shp,tiff,wms,wfs,postgis). The eclipse environment offers you ease of configuration to build your own gis-cleint.
• gvSig is a free multi langual gis-client in java by a spanish firm (wms, wfs). (http://www.gvsig.gva.es )

Basic clients

openEv is a basic gis-viewer by frank warmerdam (http://fwtools.maptools.org/ )

development environments

Lots of groups offer platfoms in which you can easily build your own desktop gis client.

http://www.geovistastudio.psu.edu

http://www.vividsolutions.com/jts/jtshome.htm

http://openmap.bbn.com

Free clients
- the guys at http://www.tatukgis.com created a Delphi.net environment in wich you can build your own viewer with a few clicks. But they also offer e simple viewer for free. Tatuk manages to put all gis-functionality in just a tiny 10mb application.

soon to come
- At http://fmaps.sourceforge.net they are coding to bring a decent gis-client to the linux-platform. They use postgis to store data.

sql-flavours

when talking to lots of databases you notice there are many flavours of sql. Once in a while it drives me crazy to get for example the syntax for a limit in db2 and so on. Recently i found a nice overview of the different flavours: http://troels.arvin.dk/db/rdbms/ So now we all know that a limit in db2 sql = 'FETCH FIRST n ROWS ONLY'

bbbike.de (open source navigation)

We recently discoverded an open source navigation tool (to calculate shortest distance between points of interest) at www.bbbike.de It can be used as a standalone perl desktop application or in combination with mapserver as a server based navigation tool on the web. Good work, as far as we know, the first open source navigation map.

Eclipse all-in webdevelopper

We recently changed to using Eclipse as a web-editor. Eclipse is an open-source editor which has been designed to program java-applets, but in the meanwhile lots of other tools have been incorporated to support web-development in general. Now we can use 1 tool to edit web-templates, look in to jdbc-databases (oracle,mysql,postgres), do file-comparissons and cooperate using version management.

A special plug-in is available to work with cold fusion (cfeclipse) this plug-in has equal capacities as studio/homesite (like syntax highlighting,collapsing).

Another nice thing is that it runs on java and you don't need to install anything to get eclipse going, so if we visit a customer where we do not have lots of privileges, we copy eclipse to the harddrive and start working.

Some disadvantages are: the total code is at least some 200mb of files (huge download) and it runs on the java-platform which sometimes gives some performance issues on windows computers.

Mapserver virtualspatialdata

It's a long time ago since i posted something here... (got married in the meantime). These days we are working on an application in which users can insert point-data in an mysql-table. The data is displayed in the map afterwards.

The application is based on chameleon/mapserver. To present the data virtualspatialdata is used. The mapserver Wiki gives a clear description on how to implement is. However i'd like to point you on a single issue.

When i first tested my virtual ogr file using ogrinfo (on a windows 2000 sp3 server), I recieved messages that the file gcs.csv could not be opened, containing the projection information.

ERROR 4: Unable to open EPSG support file gcs.csv. Try setting the GDAL_DATA environment variable to point to the directory containing EPSG csv files.
ERROR 1: Failed to import LayerSRS `EPSG:28992'.

The reason was that i hadn't run setenv.bat.

Later when i tried to view the virtualdatalayer in mapserver i got the same messages. Apparently mapserver/apache/ogr also didn't know where to look for the projection-files. After introducing the parameter gdal_data in apache config the layer was displayed properly.

SetEnv gdal_data "/ms4w/tools/ogr-utils/data"

Good luck trying out yourself.