Geometry Technologies was a company that specialized in the development of scientific and mathematical software, with a focus on visualization and the use of the web to convey scientific and other technical information. Geometry Technologies originally grew out of the Geometry Center at the University of Minnesota, and eventually evolved into my solo consulting business.

Since 2015 I am the Chief Technology Officer at FernLeaf Interactive, and Geometry Technologies is no longer active as a business. I maintain this web site as a record of what I have done in the past, however, and as an indication of the kind of work I like to do.

I enjoy bridging the gap between science or mathematics research, and high quality software development. I am a mathematician by training, and I bring the precision and thoroughness of a mathematical mind to software engineering. I love to bring science and math to life in software, turning scientific exploration and discovery into robust, working systems that help people understand and communicate ideas about how the world works.

Mark Phillips

March 2015


FernLeaf Interactive

FernLeaf Interactive is an envionmental data analytics and visualization company. FernLeaf builds cloud-based software for understanding and visualizing the complex relationships between climate, the environment, and valued assets.

Interactive Watershed Visualization

This application shows how water flows across land. It lets you immediately see all the area that is both upstream and downstream from any location in the United States. It's based on data from the USGS, is written in JavaScript using Leaflet.js and topojson, and uses HTML5 Canvas rendering to provide fast interactivity. It works in any modern desktop or mobile web browser. You can check it out yourself; the source code is on github. You can watch a video of me giving a 10 minute !!Con 2016 talk about it on youtube.

Interactive US Temperature Trend Visualization

This application shows long-term temperature change in the 20th century at about 2000 NOAA weather-monitoring stations across the United States. I wrote this as a demonstration of one way to visualize a large amount of station-based time series data; it's not intended to be any kind of scientifically precise statement about climate change, although it does use real temperature data from NOAA's GHCN daily data set. It's written in JavaScript using Leaflet.js for the map, and Multigraph and d3.js for the graphs. Here's a short video screencast that explains the application. The application source code is on github. I did the data analysis in Clojure using Incanter; my Clojure code for this is also on github.

Geometry Sketching Program

This ClojureScript program was inspired by Geometer's Sketchpad. Use it to create interactive geometry diagrams. View the source code at

Triangle Peg Solitaire Solver

This is a JavaScript program that solves the triangle peg solitaire puzzle, using the HTML5 canvas element for animated graphics. I wrote this mostly just for fun, and to have a small project that I could use for experimenting with various styles of JavaScript coding.


Multigraph is software for creating two-dimensional scientific data graphs in web pages. It can read data in a variety of formats, and allows the user to customize the appearance of the graph. Multigraph provides interactive "pan" and "zoom" capabilities, giving the viewer the ability to change the horizontal and/or vertical scales in the graph on the fly. Multigraph also has the ability to read data from a web service, which allows it to be used to "surf" through large datasets, downloading only those the parts of the data that are needed for display.

Multigraph is used extensively on NOAA's National Climatic Data Center web site, and on the NOAA site. You can read more about Multigraph and see other examples at the Multigraph web site

Integrated Station Information System

ISIS is a very flexible storage and management system for metadata related to weather and climate monitoring stations. It provides for entry, viewing, and storage of arbitrary metadata schemas, and tracks and displays the history of metadata values over time, as well as current values. It is used to track information for NOAA's CRN (Climate Reference Network), HCN-M (Historical Climate Network - Modernization), CHIP (COOP Historical Integration Project), and HPN (Hawaii Precipitation Network) stations.

Geometry Center

The Geometry Center was a National Science Foundation Center for Science and Technology at the University of Minnesota that was funded from 1990 until 1998. The mission of the Geometry Center was to explore ways that computers and computer graphics could be used to help research, understand, communicate, and teach mathematics. The Geometry Center pioneered some of the most innovative scientific and mathematical visualizations of the time, and developed one of the first web sites in existence, with some of the first experimental interactive web (CGI) applications. Although the Geometry Center closed in 1998, its web site is still available online. Geometry Technologies Inc. was founded in 1998 with the mission of carrying forward some of the work begun at the Geometry Center.


COMAP (Consortium for Mathematics and its Applications) is a non-profit agency that develops and disseminates mathematics curriculum materials. Geometry Technologies developed an interactive online subscription and library system for COMAP, as well as several web-based applications to support collaboration and communicate between authors and teachers. We also developed online registration systems for two student math contests that COMAP puts on each year, MCM (Mathematical Contest in Modeling), and HiMCM (High School Mathematical Contest in Modeling).

Science U

ScienceU is an interactive online science and math museum. It was developed initially at the University of Minnesota Geometry Center in 1997 and 1998, and then further by Geometry Technologies Inc. Development of ScienceU stopped in 1999 due to lack of funding, but we have kept the site online because we like it so much and because it showcases some of our early web development work.


Geomview is an interactive 3D viewing program for Linux and other flavors of unix. Geomview was written at the Geometry Center at the University of Minnesota between 1992 and 1996, by me (Mark Phillips), Stuart Levy, Tamara Munzner, and a lot of other people. Although the Geometry Center closed in 1998 and Geomview is no longer actively developed, it is still used by many people around the world. It is open source software and is available from the Geomview web site. Geometry Technologies provides support and custom development for Geomview users.

Climate Reference Network

The Climate Reference Network (CRN) is a network of climate monitoring stations currently being developed by the US National Oceanic and Atmospheric Administration (NOAA). Its main goal is to provide extremely accurate observations of temperature and precipitation for the purpose of better understanding of long-term climate change. Geometry Technologies provides software development and support for CRN at the National Climatic Data Center NCDC in Asheville NC. This includes software for data ingest, database design, data storage and retrieval, monitoring, metadata management, web display, graphical display, and scientific research.