July 5, 2023

A Brief History of Global Mapper – Part 1

Written by: David McKittrick


As a Global Mapper user, have you ever taken time to contemplate the important role that the release of Windows 95 had in the early development of your favorite GIS application? I thought not. There’s a strong possibility that many of you readers were but a twinkle in your parents’ eyes when Bill Gates and his cohorts borrowed a classic Rolling Stones number and awkwardly frolicked around the stage while our Windows 95 computers beseeched us to “Start Me Up.” 

Global Mapper was originally called dlgv32, made by the USGS

It seems that the folks at the USGS were looking past the ungainly dancing and paying close attention to this personal computing innovation. The newly revamped, graphics-friendly computers now sitting on everyone’s desks were the inspiration that the agency needed to embark on a project to develop a freeware application for viewing their burgeoning collection of data. The lead developer on this project, which would culminate in a product called dlgv32, was a certain Mike Childs, whose name would become synonymous with Global Mapper over the subsequent two decades.

If the truth be told, dlgv32 is not a name that smoothly rolls off the tongue, but there is a certain 1990s logic to the moniker.

  • DLG – Digital Line Graph was the name given to the USGS vector data files
  • V – Viewer
  • 32 – a 32-bit operating system, which the application supported

dlgv32 original Global Mapper

Compared to today’s Global Mapper, dlgv32, which was released in June of 1997, was bare-bones, to say the least. Supporting just one file format and with no analysis, editing, or even exporting capability, it really lived up to the “V” in its name. It was a viewer. That’s all. Nonetheless, dlgv32 was a resounding success. According to USGS statistics, the application was downloaded an average of 100 times each day, with a total of 60,000 copies in circulation after the first two years.

Just a month after dlgv32 version 1.0 was released, version 1.5 was completed boasting support for the USGS DRG data, the agency’s raster topographic maps. This rapid functional upgrade was the first example of what would later become one of the defining characteristics of Global Mapper: its continual state of development.


Dlgv32 Evolves into Global Mapper

Subsequent releases of dlgv32 added support for newly available USGS terrain datasets, including the option to apply a shader to represent variations in elevation. They also saw the introduction of an innovative and, at the time, unique reprojection process that applied the active projection parameters to all data layers as they were loaded — a function that users of the current release of Global Mapper still appreciate.

With this enhanced functionality and expanding format support, it became clear to the folks at the USGS that dlgv32 was developing beyond the agency’s original directive, so they made the decision to release the source code for commercial development. Who better to take up the mantle than Mike Childs?

September 2001 saw the release of dlgv32 Pro for the modest price of $79. More significantly, it opened the door for Mike to independently address the needs and requirements of the growing user community and to create software in response to customer input with no bureaucratic overseers. Technically this first commercial release was version 4.0, a numeric naming sequence that continues to this day.


Early Highlights of Global Mapper Development

Over subsequent releases, many of the capabilities seen in the current release of Global Mapper were introduced:


  • Version 4.27 – The workspace file for saving the display of loaded layers.
  • Version 4.28 Scripting as an alternative means of processing data.



  • Version 5.0 – The Digitizer for drawing or editing vector objects. Also the Image rectification tool for geographically registering raster layers.


  • Version 5.08 – Gridding for creating a raster surface model or DEM from 3D vector data.
  • Version 5.09GPS tracking using a connected GPS receiver. This development followed just a few years after the removal of Selective Availability by the U.S. Government, which significantly improved the accuracy of GPS positioning and resulted in a rapid upsurge in the commercial use of GPS technology.

Global Mapper was Made for Users and Their Uses

After just three years of focused development, Global Mapper had already begun to gain considerable attention in the GIS community, not only within the U.S. but throughout the world. This occurred in spite of the fact that there was no formal marketing or proactive business development effort. Most early users cited word-of-mouth recommendations from colleagues or clients as the primary reason that they initially found out about the software.

These early users were also instrumental in steering the continued evolution of Global Mapper. Reacting to requests from individuals, Mike would frequently create an update to the software and deliver a unique build to the requester, often within a few hours of the initial contact. This was a mutually beneficial arrangement: Mike was able to develop functionality that specifically targeted the needs and requirements of a particular industry and was able to lean on the requester to test the new functionality before it was incorporated into the general release version. The requester benefited from the fact that they received a version of Global Mapper that was customized to meet their needs. While Global Mapper has matured considerably since these early years and now follows a more formal development and release process, this underlying reactionary development philosophy is still prevalent today.

It is worth noting that for much of this journey, Global Mapper remained under the singular charge of Mike Childs. Many users have expressed amazement that the software gained a worldwide following with just one person at the helm. Mike was somehow able to concurrently develop, distribute, and support Global Mapper with minimal assistance. Stories of Mike responding to customer questions at ten o’clock on a Saturday evening, during which he would not only provide one-on-one assistance but would often tweak the code and deliver a custom build, are the stuff of legend. While Global Mapper has developed significantly since these early days, this direct interaction with customers is still an essential part of its development process.


Global Mapper Development Accelerates

Global Mapper version 6, released in late 2004, brought the introduction of several significant new features and functions, including the 3D Viewer for rendering a three-dimensional model of terrain data, support for displaying online data (initially limited to TerraServer imagery), the introduction of the batch conversion tool, and support for several new formats including JPEG2000. As a consequence of this expanding functionality, version 6 also saw a price increase from $99 to $199. This rapid development cycle continued with each successive release:



  • Version 8 – Support for Web Map Services (WMS), KML/KMZ support, and several raster display options, including feathering and color balancing.


  • Version 9 – Support for OpenStreetMap vector files, lidar (.las) export, JPEG2000/ECW export, and the Combine/Compare Terrain function for analyzing overlapping terrain surfaces.


  • Version 10 – The Coordinate Converter tool, support for Esri personal geodatabases, CoGo (Coordinate Geometry) for digitizing from known feature dimensions, support for loading photos as clickable picture points based on embedded geotag information, support for tracking multiple GPS devices.


  • Version 11 – Introduction of a 64-bit version of Global Mapper, support for exporting geospatial PDF files, 3D vector rendering, buffering vector features, and vector display based on specified attributes (thematic mapping).


  • Version 12Watershed tool for delineating stream networks and catchment areas, online access to NAIP imagery, US 10-meter NED, and global ASTER GDEM terrain data, support for grouping layers in the Overlay Control Center, support for creating vector polygons from colors or elevation ranges in raster layers.


  • Version 13 – Density visualization (heat mapping), attribute joining and calculating, Image Swipe tool for pulling back a raster layer to see underlying data, support for Esri file geodatabases, and network licensing.


Blue Marble Acquires Global Mapper

At the end of 2011, Global Mapper would undergo its most significant transition since its inception 14 years earlier. Maine-based Blue Marble Geographics, a modest geospatial software company widely known for its expertise in coordinate conversion and geodetics, acquired Global Mapper. Thankfully to all concerned, they also acquired the services of Mike Childs. This acquisition proved to be a win-win-win arrangement:

  • Blue Marble won (obviously) because they were able to add Global Mapper to their suite of software offerings.
  • Mike Childs won because he was able to utilize Blue Marble’s sales and support team allowing him to devote more of his time to developing the software. Rumor has it he may have also benefited financially.
  • Finally, Global Mapper users won because, in the ensuing years, the software’s functionality and prominence would grow exponentially, emboldened by an expanding crew of Global Mapper developers, an eager and enthusiastic support team, and a dedicated group of globetrotting sales and marketing specialists.

In the next installment of the History of Global Mapper Part II, we continue the epic saga of Global Mapper and recount the Global Mapper development highlights over the last thirteen years, culminating in the version 24.1 release. 


Companies using Blue Marble’s geospatial technology