Every year, there is an international gathering of geospatial software geeks working in open source somewhere in the world. This has become known as the FOSS4G conference–with the “F” preferentially standing for “Freedom” rather than just “Free”. The last one of these I attended in person was a long while ago in Sydney (2009!). Since then, I have attended a couple of the local Oceania editions and even served on the board of the non-profit that organizes them, but this was my first global one in a long time.
It was great to see the community still alive with a lot of energy, attracting around 400 people from around the world to Tāmaki Makaurau.
Travel and Weather: The Metallica Tax
November in Auckland is very pleasant. Perhaps that is what drew so many events there at once. Accommodation was expensive to unaffordable due to a Metallica concert and an Indigenous education conference happening simultaneously. There were, of course, amazing shows and entertainment on offer as a result, but my wallet definitely felt the “Metallica Tax”. I ended up staying a 30-minute bus ride away from the city centre in Takapuna, which gave me some nice morning views of the Hauraki Gulf before diving into the windowless conference rooms.
Tutorials: Rust, AI, and No-Code Flows
EO with Rust - Leo Hardtke
Leo Hardtke’s tutorial was all about making Earth Observation (EO) processing faster with Rust and without the Python overhead. It was, however, plagued by Nix vagaries and the classic environment distribution issues that seem to follow “modern” build systems everywhere. When it worked, it was blazing fast. The code is available on GitHub for those brave enough to venture into the world of memory safety and zero-cost abstractions.
AI in the Frontend - Felix Palmer
Felix Palmer showed off a cool Claude-enabled frontend to make Deck.gl do things in response to free-text commands. Zooming and searching is just the beginning; we can also do custom frontend processing using the frontend equivalent of GEOS, Turf.js.
I hit a snag here: I could not get my account activation SMS from Claude while in NZ (roaming issues, I suspect). So, in true maker fashion, I ported the code to work with AWS Bedrock instead. It’s a good reminder that in the world of LLMs, being tied to a single API is a recipe for frustration.
Re:earth Flow - Kyle Waite
This was perhaps the most interesting tutorial from an open-source and national policy perspective. I often insist that science developers learn programming, but sometimes for adoption, this is simply not a feasible change. This is what creates room for numerous commercial and open-source tooling for GUIs and no-code/low-code workflow systems like FME, ESRI, and even the QGIS toolbox.
As part of the Plateau project, the Japanese government is putting together the “Flow” framework for prefectures to process and convert their own 3D models. The intro to the UI tools was amazing, and in time, it seems like it can challenge FME. The state management is done by y.js, and we had a fun time getting multiple users to modify the flow until it broke in spectacular fashion.
Presentations: The ones that stuck with me among many excellent ones
For the full roll of presentations check out the 150+ youtube playlist.
The Java Geospatial Ecosystem - Jody Garnett
Jody Garnett gave a deep dive into the state of the art behind the libraries doing the heavy lifting in the Java Geospatial ecosystem: JTS, GeoTools, and the long journey behind getting the Java Imaging library ported to an open-source equivalent supported by the Eclipse foundation. It’s a reminder that while Python gets the hype, a lot of the world’s spatial data still moves through Java pipes. I ended up also going to his talk on Geoserver, which keeps being a force to reckon with in serving GIS data at scale.
GPU Accelerated Zarr Loading - Wei Ji
Wei Ji’s presentation on GPU-native Zarr was a highlight. Optimizing data throughput for large-scale geospatial ML workflows is the new frontier, and moving the bottleneck from the CPU to the GPU is where the real gains are.
Is Zarr the new COG? - Jarrett Keifer and Julia Signell
An excellent presentation dispelling the hype around Zarr. The takeaway? Given the same input and compression, the resulting content is the same size. It’s the usage pattern and the “tyranny of chunking” that really affects performance, along with the fine points about using multiple files, shards, and inodes.
Navara Web3D Engine - Keiya Higuchi
The Re:Earth folks returned with Navara, a re-imagined 3D engine for the web using a modern stack including WebGPU. It aims to create more options for realistic rendering and a functional separation between GIS functions and visualization functions–which are often messily intertwined in current offerings.
STAC Adventures with Matt Hanson
One of the most fun presentations was Matt Hanson’s “Choose Your Own Adventure” session. He let the audience pick the path in D&D fashion to learn more about the STAC ecosystem. I threw in my two cents on the fact that “not all STAC is made equal” and the desperate need for conformance checks on hosting services that claim to be STAC compliant but fail in subtle ways that break downstream libraries.
ESA’s Zarr Foray - James Banting (SparkGeo)
ESA is restructuring the Sentinel satellite imagery archive into DGGS / Healpix Zarr format and publishing the EOPF toolkit. The SparkGeo presentation showed the state of implementation of the user-facing libraries and how they are being integrated into various tools.
After Parties: Hazy Hops and Community
The conference after-parties at the pub are where most of the real action happens. I spent my evenings hanging out with a mix of old friends and new faces, trying the famous New Zealand hazy hops. There’s something about a good IPA that makes discussing coordinate reference systems much more bearable.
