Our university offers free access to ArcGIS Online and ArcGIS Pro to all students, faculty, and staff.  Here are short introductions to each platform:

• ArcGIS Online: ArcGIS Online is a cloud-based mapping platform from Esri that lets you create, share, and analyze interactive maps and data without installing special software. It’s best for quickly making web maps, collaborating with others, and accessing ready-to-use geographic data and analysis tools. 

• ArcGIS Pro: ArcGIS Pro is Esri’s powerful desktop GIS software for creating, analyzing, and managing geographic data in 2D and 3D. It’s best for in-depth spatial analysis, advanced map design, and working with large or complex datasets. Researchers and professionals use it to perform detailed geoprocessing, customize workflows, and integrate data from multiple sources to produce high-quality maps and analyses.

Although DU's GIS software offerings are focused on Esri products, several other popular platforms and applications are available for you to explore.

Desktop GIS Systems

• QGIS: A full-featured desktop GIS for mapping and spatial analysis. Supports many data formats and plugins. Ideal for students, researchers, and professionals wanting a powerful free alternative to ArcGIS Pro.
• GeoDa: A free, user-friendly desktop software package that excels at exploratory spatial data analysis (ESDA). It's best for researchers, social scientists, and analysts who are working with vector data (like census tracts or crime locations) and want to statistically test for and visualize geographic patterns without needing a full-blown GIS program.
• GRASS GIS: Geographic Resources Analysis Support System is a comprehensive GIS software suite for advanced geospatial analysis and modeling. Strong raster and scripting capabilities. Good for environmental, hydrological, or terrain modeling projects.
• SAGA GIS: System for Automated Geoscientific Analyses is a GIS application with a primary focus on providing scientific and statistical analysis of raster and terrain data. It is particularly strong in the analysis of raster data, with a wide array of tools for terrain analysis, hydrological modeling, and climate studies. Known for extensive geoprocessing algorithms. Strong choice for environmental sciences and academic research.
• WhiteboxTools / Whitebox GAT: Best for fast, command-line geoprocessing and terrain analysis. Helpful for automation, batch-processing tasks, and integration with Python.
• gvSIG: The desktop version, gvSIG Desktop, is a versatile and user-friendly GIS client that allows users to work with a multitude of vector and raster formats, as well as remote services. 
• uDig: User-friendly Desktop Internet GIS is an open-source desktop application framework, built with Eclipse Rich Client Platform technology. It is designed to be a user-friendly GIS that can be used as a standalone application or as a component in other applications. uDig emphasizes a "drag and drop" interface for ease of use. 
• OpenJUMP GIS: It is an open-source GIS written in the Java programming language. It is known for its robust vector analysis and editing capabilities. OpenJUMP is a flexible and extensible platform with a community that has developed numerous plugins to enhance its functionality. 

Web-Based (or Browser-Accessible) GIS Tools

• Google Earth Engine (GEE): A cloud-based platform designed for planetary-scale environmental data analysis. It combines a massive, multi-petabyte catalog of satellite imagery and geospatial datasets with powerful computing capabilities. GEE is not for making simple maps. It's best for running complex algorithms on vast amounts of raster data to detect large-scale changes, map trends, and quantify differences on the Earth's surface over time, such as tracking deforestation, urbanization, or water resources.
• Mapbox Studio (Free Tier): A web-based design tool for creating beautiful, custom basemaps and data visualizations for web and mobile applications. It's best for developers and designers who need complete creative control over the look and feel of their maps, from colors and fonts to 3D building extrusions. The free tier is generous, allowing you to design and publish custom maps that can handle a significant number of views, making it perfect for startups, personal projects, and developers who need a powerful mapping API.
• Kepler.gl: A powerful, open-source, web-based tool for visualizing large-scale geospatial datasets. It's designed for the quick and intuitive exploration of massive location-based datasets, like millions of trip records or GPS points. Kepler.gl is best for data scientists and analysts who need to quickly drag-and-drop a large dataset into a browser and instantly see it rendered on a map, allowing them to filter, aggregate, and animate it in 2D and 3D to uncover patterns on the fly.

Desktop GIS Software 

For General-Purpose & Professional GIS

• Use ArcGIS Pro if... you are a GIS professional, student, or organization working within the Esri ecosystem, or if it is the industry standard for your field. It's a powerful, all-in-one application for advanced analysis, sophisticated cartography, 3D visualization, and managing large, complex geospatial databases.

• Use QGIS if... you need a powerful, free, and open-source alternative to commercial software. It's the best choice for users who need a full-featured, all-around GIS for professional map-making, a wide range of analyses, and extensive data format support without the cost of a software license.

For Heavy-Duty Scientific Analysis

• Use GRASS GIS if... your work involves complex, scriptable, and repeatable scientific analysis, especially with raster data. It's a powerful tool for academic research, environmental modeling, and hydrology, but has a steep learning curve.

• Use SAGA GIS if... your primary focus is analyzing terrain and raster data. It offers a massive library of specialized geoscientific algorithms for things like hydrological modeling and landform analysis.

• Use GeoDa if... you need to explore spatial patterns in your vector data. It's not a full GIS, but a specialized tool for finding statistical "hot spots," "cold spots," and other spatial clusters in data like crime incidents or census results.

For Niche & Specialized Tasks

• Use OpenJUMP if... you need to perform complex editing and cleaning of vector data (points, lines, polygons).

• Use gvSIG if... you are working within its ecosystem, which includes strong mobile and enterprise options for field data collection and asset management.

• Use uDig if... your main goal is simply to view standard GIS data formats and consume web map services with an easy-to-use interface.

Web & Cloud-Based Platforms

For Collaboration, Sharing & Field Apps

• Use ArcGIS Online if... your main goal is to share maps and collaborate with a team or the public. It is the central hub of the Esri ecosystem, excelling at creating interactive web maps, dashboards, and mobile apps for field data collection (like surveys and asset inventories).

For Big Data & Planetary-Scale Analysis

• Use Google Earth Engine (GEE) if... you need to analyze enormous, planetary-scale satellite imagery datasets. It's a specialized tool for running algorithms on petabytes of environmental data to track large-scale changes like deforestation or surface water change over time.

For Custom Design & Web Development

• Use Mapbox Studio if... you are a developer or designer who needs to create beautiful, custom-designed basemaps for a website or mobile app. Its focus is on cartographic design and developer APIs, not deep analysis.

For Quick Visualization of Large Datasets

• Use Kepler.gl if... you have a very large dataset of points or lines (like millions of taxi trips) and need to quickly drag-and-drop it into a browser to visualize and explore it instantly in 2D or 3D.