GRASS Community Meeting Prague 2023

From GRASS-Wiki
Jump to navigation Jump to search

The GRASS GIS team organized a GRASS GIS Community Meeting with contributors, power users and developers from June 2 to June 6, 2023 to celebrate GRASS GIS 40th birthday (by contributing to GRASS GIS of course).

Quick links: Full activity report | Sponsors | Press release


GRASS GIS Community Meeting is a great occasion for folks to support the development by actively contributing to the source code, documentation (manuals, wiki, tutorials), translations, website or likewise. The community meeting is also a get-together where supporters, contributors, power users and developers make decisions and tackle larger problems related to the project, discuss and collaboratively resolve bugs, plan the direction for the project and work on new features. We welcome people committed to improving the GRASS GIS project and the interfaces to QGIS, GDAL, PostGIS, R, OGC Services and desiring to celebrate with us the 40th GRASS GIS birthday!!

In this meeting, we will work on GRASS GIS and integrations with related OSGeo projects. We will revise connection to QGIS to make it easier to maintain, and we will work on migration of the build to CMake to improve Windows builds including PDAL support. Furthermore, we will start moving documentation to Markdown to make it easier to contribute to and we will add images and examples for tools and workflows which still miss them. Finally, we will automate and document maintenance processes to reduce the burden on maintainers and thus improve the project sustainability.

Note that while we have our general plan, we can't accept any earmarked donations, i.e., we can't make any promises for a specific work to be done. We do require participants to work on GRASS GIS or connections to other projects. However, we leave them the freedom to work on what they think is the best contribution to the project at that time given their skills and time available.

For the detailed agenda and individual's plans, see below.


We welcome financial contributions to support the meeting and we are looking for sponsors to cover costs such as meals or to help reducing travel and accommodation expenses for GRASS developers who volunteer their time. If you are interested in sponsoring the GRASS Community Meeting, please see our

OpenCollective GRASS Community Meeting Prague 2023 Tier

Any surplus at the end of the event will used for future activities of the GRASS GIS project such as the successful student mini grant program.

This GRASS Community Meeting is a great occasion for you to support the development of GRASS. With your contribution you'll enable more developers to meet. Community meetings are important opportunities for developers to discuss, fix bugs, plan the direction for the project and work on new features. Please see below for the detailed agenda. The developers and contributors are donating their valuable time, so it would be great if in-kind funding can be made available from within the community to cover out-of-pocket expenses. All of the work that takes place at the community meeting will be directly contributed back into the GRASS project to the benefit of everyone who uses it.

Thanks to our sponsors

We are grateful for the support which we have received to organize this GRASS Community Meeting:

Light and dark green logo of OSGeo saying Your Open Source Compass
Open Source Geospatial Foundation
Logo of FOSSGIS e.V.


  • Hernán De Angelis 20 USD
  • MarWe 50 USD
  • Nick Brady 50 USD
  • José Ramón 50 USD
  • Bon 50 USD
  • Johannes Brauner 30 USD
  • Peter Löwe 30 USD
  • Evan Kay 10 USD
  • Joaquin Perez Valera 5 USD
  • Anonymous sponsors 2750 USD

In-kind contributions:

  • Department of Geomatics Faculty of Civil Engineering Czech Technical University in Prague (FCE CTU) - space and personnel time (planning, preparation, participation)
  • North Carolina State University, Center for Geospatial Analytics - personnel time (planning, preparation, participation)
  • mundialis GmbH & Co. KG - personnel time (planning, preparation, participation)
  • CONICET - personnel time (planning, preparation, participation)
  • Research Institute for Nature and Forest (INBO | Brussels, Belgium) – personnel time + travel and hotel costs of INBO staff
  • SunGIS – personnel time, travel, and hotel costs of Maris Nartiss
  • OpenPlains Inc. – personnel time

Personal time and/or financial contributions:

  • Martin Landa, Micha Silver, Helmut Kudrnovsky, Markus Neleter, Ondřej Pešek, Helena Mitasova, Vaclav Petras, Anna Petrasova, Corey White, Maris Nartiss, Aaron Saw Min Sern, Luís de Sousa, Caitlin Haedrich, Linda Kladivová, Carmen Tawalika, Floris Vanderhaeghe, Eva Stopkova, Brendan Harmon, Veronica Andreo, Daniel Torres, Loïc Bartoletti


When: June 2-6, 2023

Of course you are invited to join or leave the meeting whenever you want.


Department of Geomatics
Faculty of Civil Engineering
Czech Technical University in Prague, Czech Republic
Thákurova 7/2077, Prague
Room B868

Prague has an international airport and is also reachable by train, bus or car.

Accommodation and Costs

Participants should plan for the following costs:

  • The participation is free of charge
  • Travel to Prague, variable depending on where you come from, reimbursements depending on the financial contributions provided by the community
  • Accommodation and meals (with the donated sponsorship money we will try to cover some expenses of the participants)

Please note: The currency in Czech Republic is Czech crown (CZK, koruna, Kč). 100 Czech crowns are about 4 Euros (see current rates).

Please let us know your time of arrival and departure, so we can book accommodations and organize the logistics.

Financial support: (partial) travel grants can be payed upon request thanks to our sponsors!

Agenda - What we plan to do

Note: The program is generally open for your ideas. Please write an email to the GRASS developer list to discuss your contribution.

During the meeting we will work on GRASS GIS on these tasks (please add more!):

  • We will update and revise the GRASS GIS Integration with QGIS to simplify maintenance.
  • Furthermore, we will migrate the compilation technology to CMake to significantly improve the Windows builds including PDAL support and become binary compatible with OSGeo4W.
  • The extensive GRASS documentation will be converted from HTML to Markdown to facilitate future collaboration.
  • Pictures, examples and workflows will be added to the documentation where they are still missing.
  • Software maintenance processes are automated and documented to reduce the burden on maintainers and thus improve the sustainability of the project.

This means that there are tasks from both the programming and documentation areas to appeal to a wide range of interested parties.

Further details about the action items you find here and below. Topics cover non-technical, semi-technical, and technical issues.


(agenda is under development, but also flexible)

Thursday, 1 June

  • Arrival

Friday, 2 June

  • 9:00 meeting starts in the room B-868
  • Lunch: 12:45 NTK
  • Review the plan for the next days
  • API for use in Python and in other projects (e.g., QGIS)
  • Parallelizations

Saturday, 3 June

  • Reducing cost of distribution on Windows
  • Convert GRASS GIS documentation from HTML to Markdown and implement new documentation system (mkdocs?)
  • Group photo 1
  • Outdoor social evening

Sunday, 4 June

  • Compilation CMake (Windows, Linux)
  • Connections in general, rgrass, qgisprocess
  • GRASS GIS addons overview generator for entire GitHub (and more?) based on tag "grass-gis-addons"
  • Group photo 2

Monday, 5 June

Tuesday, 6 June

  • Connections in general, QGIS
  • Parallelizations
  • grass.jupyter

Wednesday, 7 June

  • Departure

Social events

Friday, 2 June

Dinner at 7pm: U veverku pub (map)

Saturday, 3 June

Dinner at 6pm: Únětický pivovar (map)

  • 3:50pm train from Podbaba (15min walk) to Roztoky
  • walk 1:30min
  • Bus (355) back from Unetice to Dejvicka: 21:57 or 23:18

Sunday, 4 June

Dinner at 7pm: Restaurace Vltava (map)

Monday, 5 June

Dinner at 7pm: My Paprika (map)

  • Tram 26 from Dejvicka to Strossmayerovo namesti at 6:26pm


We are planning for an attendance of 20 people (i.e., coding places) but of course you are welcome to join us and bring new ideas with you: we'll make more places available. Please add your name here or contact Martin Landa <landa.martin at>:

In person

Number Participant Country Arrival Departure Topics Notes
1 Martin Landa Czech Republic June 1 June 7 Python: create_location (#1987), Graphical Modeler improvements and single window layout integration
2 Micha Silver Israel June 2 June 6 Addon to derive soil moisture from Sentinel 2
3 Helmut Kudrnovsky Austria June 2 (18:37) by train June 4 (18:24) by train support CMake transition
4 Markus Neteler Germany June 2 (17:17) June 6 (12:43) translations, manual pages, ..., see my list in "Discussion" page
5 Ondřej Pešek Czech Republic June 2 (17:17) June 6 (12:43) Python 3.12-connected issues, gmodeler
6 Helena Mitasova United States June 2 June 6
7 Vaclav Petras United States June 1 June 7 init and other Python API topics, support CMake transition, revise connection with QGIS and other tools, funding
8 Anna Petrasova United States June 1 June 7 parallelization documentation, grass.jupyter, R and QGIS integration
9 Corey White United States June 2 (10:55) June 7 Connections with other tools, OpenPlains, JSON outputs
10 Maris Nartiss Latvia June 2 (14:30) June 6 (12:00) Improvements of imagery modules (push i.svm.*; i.signatures; ?)
11 Aaron Saw Min Sern Singapore June 1 June 7 Support CMake transition, r.mapcalc parallelization
12 Luís de Sousa The Netherlands June 1 (20:00) June 5 (20:45) Update r.mblend add-on; test CMake transition.
13 Caitlin Haedrich United States June 1 June 7 grass.jupyter
14 Linda Kladivová Czech Republic June 2 June 6 Single-Window layout issues and improvements
15 Carmen Tawalika Germany June 2 (17:17) June 6 (12:43) Happy to assist with general topics like documentation + automation, in doubt something related to actinia
16 Floris Vanderhaeghe Belgium June 3 (train 19:17) June 6 (train 8:25) Helping in interfacing GRASS from R (rgrass & qgisprocess packages)
17 Eva Stopkova Czech Republic June 3 June 4 Fixing v.nnstat

If you are arriving or departing on the days of the event, please specify the time, too.

Via chat or hangout

Join our Gitter chatroom

Gitter has a video (and backup will be Zoom).

Participating virtually:

Number Participant Country Topics Times, synchronous or fully asynchronous Notes
1 Brendan Harmon United States Update integration with QGIS Available 8:00 AM CST (UTC-6) onwards
2 Veronica Andreo Argentina Mission and vision, interfaces with QGIS and R, sponsoring, ... see discussion tab available from 8:00 AM ART (UTC-3) onward
3 Daniel T Mexico some availability through the days :/
4 Loïc Bartoletti France QGIS Integration, support CMake transition

Timing of hangout meetings

Follow Gitter.

Collaborative document scratching

Follow Gitter.

Individual Preparation

  • Bring your own computer
  • Bring power connector adapter if needed (Czech Republic: 230V, 50Hz, Type C Europlugs are common and also Type E)
  • Install git and the compiler tools, and come with a working GRASS development environment if possible.

Broadcast & Video

During the event :) Find the latest information on the Gitter Channel.


Day 1

Day 2

Day 3

Day 4


  • How was it last time?
  • Is the GRASS Community Meeting just a coding event?
    • It is mainly a coding and documentation event. It is a working session for people who are already participants in the GRASS project and/or are committed to improving the GRASS project.
    • On demand we can do some presentations of current working GRASS implementation and new upcoming features to spread the idea of Open Source GIS software.
  • Is the GRASS Community Meeting for developers only?
    • No: anybody can help, with testing, checking out bugs and fixes, documentation and more.
  • Where can I get help and more information about the community meeting?

Report and press release

Published as Report of the GRASS GIS Community Meeting in Prague.

The GRASS GIS Community Meeting was held in the Czech Republic from June 2 to 6 at the Faculty of Civil Engineering of the Czech Technical University in Prague. The meeting was a milestone event to celebrate the 40th birthday of GRASS GIS and brought together users, supporters, contributors, power users and developers to celebrate, collaborate and chart the future of GRASS GIS.

Thanks to the generous funding from OSGeo, FOSSGIS e.V., OSGeo.JP, and individual financial contributors, we were able to welcome 17 in-person participants from 9 countries on 3 continents and 4 remote participants.

The meeting was not only a celebration of 40 years of GRASS GIS, a free geographic information system (GIS) software for managing, analysing and visualising geospatial data, it was also a testament to the collaborative spirit that has driven GRASS GIS for four decades. Participants worked together on various aspects of GRASS GIS, including source code, documentation, translations and the website. Participants contributed new tools, enhancements to existing ones, and a large number of bug fixes. The improvements to documentation, including onboarding materials, and a draft of the 8.3.0 release was another important outcome.

There was a strong focus on improving the sustainability of the GRASS GIS ecosystem. Several participants made progress on the CMake transition needed for improving Windows builds. Various technical discussions were held on improving the GRASS GIS interfaces to QGIS, GDAL, and R. These discussions were attended by special guests from QGIS (Nyall Dawson) and R (Roger Bivand) communities, leading to valuable insights and future collaboration plans on strengthening these GRASS integrations.

Participants submitted detailed reports outlining their contributions, collaborations and ongoing work. The event was meticulously planned, with efforts made in fundraising, budgeting, venue selection, promotion and virtual meeting organisation. Besides aforementioned financial contributions, personnel time and other costs were covered by Department of Geomatics Faculty of Civil Engineering Czech Technical University in Prague (Czech Republic), Center for Geospatial Analytics at North Carolina State University (USA), mundialis GmbH & Co. KG, (Germany), CONICET (Argentina), INBO Research Institute for Nature and Forest (Belgium), SunGIS (Latvia), and OpenPlains Inc. (USA). Special thanks goes to Martin Landa, the local host, for planning local events and keeping the participants well fed and productive.

For more details on the meeting, sponsorship, and individual reports, please visit the GRASS Community Sprint Prague 2023 wiki page, and follow us on social media (X, mastodon), join the chat channel in Gitter or the mailing lists to stay updated on future news and events. If you would like to see more developments like this in the future, please consider contributing via Open Collective.

Markus Neteler, Anna Petrasova, Vaclav Petras, Veronica Andreo, August 2023