Hot answers tagged free-software
Google Earth, for viewing and creating KMZ/KML files Trimble Sketchup, for creating 3D models PointVue LE, Fusion/LDV, LAStools, for viewing LAS (LiDAR) files in 3D PyScripter, for Python scripting ArcGIS Diagrammer 10.0, for designing geodatabases and modifying schemas (ESRI XML workspace documents) (for 10.1 and for 10.2) Visual Studio Express (C# or ...
GDAL: GDAL - Geospatial Data Abstraction Library When you don't know how to do it, you can usually do it with GDAL.
QGIS. Although I do most of my analysis using ESRI based tools, QGIS is extremely fast for quickly examining a shapefile, and zooming/panning/reading the attributes. I don't mean this in a derogatory way, as QGIS is also a wonderful open-source desktop GIS; but for quick file opening/closing it's wonderful and the quickest I've found.
Fiddler is excellent. Update Suppose I'm looking at a Web App, like Esri's Redistricting Online ... ... and I become curious about the mapservices it uses. I can fire up Fiddler and see what Urls it is accessing. I can right click and copy the url and paste into a web browser, since we're dealing with REST ... ...
Benjamin already mentioned SAGA GIS, but just the name so I would like to add more info about this excellent SW: SAGA (System for Automated Geoscientific Analyses) SAGA is also free and opensource like QGIS, but it is focused on raster data analysis and processing. The standard modules are: File access: interfaces to various table, vector, image and ...
GIMP and INKSCAPE I use these two for cartographic purposes. Gimp has good raster support (until they get huge/GB in size, then you run it on a linux OS!) and Inkscape handles vectors really well.
Java Topology Suite, particularly JTS TestBuider (for Windows users, make a Shortcut to C:\Program Files\JTS\jts-1.11\bin\testbuilder.bat). With JTS TestBuilder, you can copy/paste WKT or WKB into the geometry inputs, and debug a geometry (especially if it is invalid and you want to know why) or explore spatial functions and spatial predicate operators, ...
For statistical analysis, there is R. An integration of R with ArcGIS provides the Geospatial Modelling Environment. Using the right libraries you can easily handle shapefiles and raster data in R RStudio is a powerful IDE with debugging and improved data handling for R.
Color Oracle - a colorblindness simulator for Window, Mac and Linux. I use this for checking the "look" of my composed maps.
No-one's mentioned postgresql and PostGis yet for storing, organising and manipulating geodata.
Eclipse and PyDev for Python coding - the latest version (finally) allows you to run a script without it being in the project, and has some other great features as well (break on exception etc.). That and the almost unlimited other number of extensions that you can install in Eclipse. Git for version control. Free, easy, and you don't need to install any ...
OpenOffice/LibreOffice - I use this tool to make the maps layouts.
No one mentioned GRASS GIS or SAGA GIS...
I wonder why MAPNIK has not been mentioned yet. It is also pluged in to QGIS. Very nice tool for easily making astonishing looking maps.
The Gdal command line tools are quite useful. ogrinfo myshapefile.shp gdalinfo myrasterfile.tif ogr2ogr to convert files. Sometimes I also use the xpath tool (provided with the gnome libxml2 library) to inspect xml/xsd/kml files: cat my-insanely-complex-xml-file.xml | xpath "//Placename/text()" You get the idea.
There are lots of free GIS tools available. One of the imho best is QuantumGIS: http://www.qgis.org. It is available for win/mac and linux. But maybe you prefer openjump a tool written in java, which has special strengths in editing, topology-checking: http://www.openjump.org/ Also take a look at: http://freegis.org/
Self-link, but TileMill is very useful for exploring geodata, making pretty maps, doing analysis, etc. It's mainly for the presentation and exploration steps, while the heavy-lifting of analysis can be done in QGIS or similar.
FugroViewer - Fantastic program for viewing LIDAR data saved in LAS files. It has 2D, 3D and profile view. You can symbolize dots with all attributes stored in LAS files along with RGB colors.
Notepad++ as well as the extra settings from TWIAV.nl especially the code highlighting. Came in very handy after changing server structures as all our .wor files were broken. One short find and replace later and everything works!
You might want to try Orfeo Toolbox. OTB is based on the medical image processing library ITK and offers particular functionalities for remote sensing image processing in general and for high spatial resolution images in particular. Targeted algorithms for high resolution optical images (SPOT, Quickbird, Worldview, Landsat, Ikonos), hyperspectral ...
A great GIS that has a huge amount of functionality is QGIS. It is very easy to install especially if you use the osgeo4w installer (Windows). You can use it to view your GML file too. OSGeo is the place you want to look for OpenSource (free) GIS tools and libraries: http://www.osgeo.org/. You will find a ton of stuff here plus links to QGIS and other ...
Google Earth [Free] http://www.google.com/earth/download/ge/agree.html 400 Million Users (2008) - ESRI would be happy with half that. http://ogleearth.com/2008/07/400-million-google-earth-users-really/ More Specific GIS [Free] QGIS - http://www.qgis.org/ note: underdark (GIS Stack Exchange user might be able to give numbers of users/downloads) So to get ...
GDAL supports .img format, both the basic Imagine and the extended Imagine (greater than 2GB), thus any software that utilizes GDAL drivers would support ERDAS Imagine. The most workable and well documented that I have seen is QGIS. It is also open source and therefore free.
Don't forget to mention MapTiler for easy map tiling jobs (build on top of the already mentioned GDAL).
Maybe these links will help you: How to build effective heat-maps? with QGIS: http://alexsciuto.com/blog/2010/11/how-to-make-your-own-heat-map-pt-1-gathering-the-materials/ Python script: http://www.sethoscope.net/heatmap/ http://sk53-osm.blogspot.com/2011/01/heat-maps-from-osm-pois.html Sorry for a non elaborated answer..
Refractions Research has made a Line Cleaner tool that seems to do what you want. Line Cleaner cleanses networks by simplifying complex, cyclical, very short and zero-length geometries, and removing pseudo-nodes and insignificant vertexes. Most significantly, in the cleansing phase, it is able to ensure that feature matches can be considered ...
Only top voted, non community-wiki answers of a minimum length are eligible