Japan to the World: FOSS4G 2025 Japan Report

Introduction

On October 11 and 12, 2025, FOSS4G 2025 Japan was held at the Ikuta Campus of Senshu University. It was organized by the OSGeo Japan Chapter (OSGeo.JP), a general incorporated association.

The theme was “CONNECT TO ___”. “FOSS4G” refers to open source geospatial software, and it is also the name of conferences that promote its adoption and knowledge sharing. In 2026, the global conference will be held in Japan for the first time. The theme reportedly comes from the idea of making this year's FOSS4G a stepping stone to that global event.

This article reports on FOSS4G 2025 Japan with a focus on topics related to QGIS.

Hands-on day

Day 1 was the Hands-on Day, with six courses in which participants learned FOSS4G tools by working with them. Three of the courses covered QGIS.

Ogaya of the Japan Forest Technology Association taught “Introduction to QGIS with Forest Information.” Using open data related to forests, such as tree species polygons, the course covered basic operations like setting up symbology and managing projects, and how to read forest information.

Pikkarin's “Taking the First Step in Satellite Data Analysis” taught satellite data analysis from the ground up. Topics ranged from the basics of satellite data and how to obtain it to color compositing in QGIS and calculating NDVI (Normalized Difference Vegetation Index).

QGIS has a tool called the Model Designer, which combines the processing of several Processing tools and runs it as a single algorithm. In “Trying Out the QGIS Model Designer,” Kita of Aero Toyota Corporation gave participants a chance to experience automating an analysis process.

Courses on 3D web map libraries such as Mapray, Cesium, and Re:Earth were also held, and every course was well attended.

Core day

Day 2 was the Core Day. Across three venues, 40 presentations, including keynotes, covered topics such as QGIS, web GIS, spatial databases, and open data.

Here are a few of them, focusing on presentations related to QGIS.

QGIS plugin development case studies

In “Comparing Maps Smoothly in QGIS: Introducing the QMapCompare Plugin,” Lay of MIERUNE Inc. explained the plugin's features as its developer and presented use cases. With this plugin, you can compare maps in different styles side by side on the QGIS map canvas, either top and bottom or left and right, or reveal the stacked map beneath as the cursor moves.

For details on QMapCompare, see the article below.

Plugin development also came up in “Making the Most of 3D in QGIS” by Wayama and Itagaki of Northern System Service Co., Ltd.

The presenters described their experience of vibe coding with generative AI. They shared what they learned about using generative AI in GIS development while building a plugin that works with QGIS to display 3D models of other celestial bodies.

Data preparation case studies

In “Making the Existing Vegetation Map 2024 Easier to Use,” Yamashita and Matsumoto of the Biodiversity Center of Japan, Ministry of the Environment, and Mizutani of Ecoris Inc. described how they organized the attribute information in the existing vegetation map, fixed defects in the data, and published it as the new “Existing Vegetation Map 2024” on the Environmental Geoportal.

They also presented an effort to prepare the data as vector tiles and raster tiles (not yet public) so that it is easier to use in QGIS. Besides use cases, the presentation explained the characteristics and appeal of vegetation map data.

Shiromizu and Kato of MIERUNE Inc. gave the presentation “The Past and Future of Rekichizu: Aiming for Historical Maps Anyone Can Understand.” It introduced Rekichizu, a project that presents Edo-period maps in a modern design familiar to everyone.

The data in Rekichizu, such as highways, coastlines, and points, was created by hand in QGIS with old maps as references, so the project also drew attention as a use case for QGIS. The data is published as open data and can also be used in QGIS.

From Japan to global!

In 2026, the international FOSS4G conference will be held in Japan for the first time.

In “FOSS4G: Past and Future,” Iwasaki, representative director of the OSGeo Japan Chapter and professor at Tottori University, looked back on past activities and presented the concept and vision of FOSS4G Hiroshima 2026, along with a passionate message about getting ready to host it.

The official website of the OSGeo Japan Chapter lists information on FOSS4G events in Japan. Take a look if you are interested.

Conclusion

You can watch the livestream archive of the presentations at FOSS4G 2025 Japan on the OSGeo.JP YouTube channel.

Because the international conference FOSS4G Hiroshima 2026 will be held in 2026, FOSS4G Japan will not take place. This global event should be a valuable opportunity for developers, contributors, and users from Japan and abroad to meet.

QGIS LAB will keep bringing you FOSS4G topics, with a focus on QGIS!