Mantid Developer Meeting and User Workshop

3 Nov 2025, 08:30 → 6 Nov 2025, 19:35 Europe/London

Visitor Centre (Rutherford Appleton Laboratory)

Sarah Foxley (STFC), Stephen Cottrell (STFC)

The Mantid Developer Meeting and User Workshop will be held Monday 3rd to Thursday 6th November, 2025 at the Rutherford Appleton Laboratory in the UK.

The week will start with the Developer Meeting (Monday 3rd November for three days), giving an opportunity for the various development teams to meet to discuss the latest issues connected with the development of Mantid. The meeting will include the popular 'What has always bugged me about Mantid is ...' activity. It will also include presentations as part of the afternoon sessions. The developer meeting will be open to new and experienced developers contributing to Mantid. It is unlikely be of interest to the wider user community.

The week will continue on Thursday 6th November with a User Workshop. All Users and Developers are welcome to attend this meeting, which will include a mixture of scientific and technical talks, updates about the Mantid project and discussion about upcoming features. Note that this has recently been revised to run as a one day meeting.

In-person places at the Developer Meeting are now full but you can still sign up to attend remotely. The User Meeting will be Hybrid throughout. Please indicate how you would like to participate in the meeting when you register.

Monday, 3 November

08:30 → 10:00 Developers Meeting - In Person: Badging and Welcome

In person session at the developers meeting

Convener: Sarah Foxley (STFC)

08:30 Visitor Badging

Receive badges at the Visitor Centre

Please note this is separate from registering for the facility. Please allow enough time for facility registration before Visitor Badging.

Badges will be required for lunch.

09:00 Welcome

TBC

09:15 Overview

An overview of the developer meeting and what to expect

Speaker: Sarah Foxley (STFC)

09:30 Icebreaker

Split into groups for the icebreaker Two Truths, One Lie

10:00 → 10:20 Morning coffee break

10:20 → 12:00 Developers Meeting - In Person: Facility Updates

In person session at the developers meeting

Convener: Sarah Foxley (STFC)

10:20 Facility updates

Facility updates aimed at Developers

• ISIS

Speaker: Sarah Foxley (STFC)

12:00 → 13:00 Lunch

Badges required

13:00 → 14:45 Developers Meeting - In Person: Meta Hackathon

In person session at the developers meeting

Convener: Caila Finn (STFC)

13:00 Hackathon of Hackathons - Introduction

Talk from Caila about recent Hackathon at ISIS and set up for the activity

Speaker: Caila Finn (STFC)

13:30 Hackathon of Hackathons - Part 1

Speaker: Caila Finn (STFC)

14:45 → 15:15 Afternoon coffee

15:15 → 16:45 Developers Meeting - In Person: Hackathon of Hackathons (continued). Preparation for Tuesday Code Camp.

In person session at the developers meeting

Conveners: Caila Finn (STFC), Peter Peterson (Oak Ridge National Laboratory)

15:15 Meta Hackathon - Part 2

Includes feedback and summary

Speaker: Caila Finn (STFC)

16:15 Prep for Tuesday code camp

Speakers: Peter Peterson (Oak Ridge National Laboratory), Sarah Foxley (STFC)

Tuesday, 4 November

08:30 → 09:00 Coffee and networking

09:00 → 12:00 Developers Meeting - In Person: Code Camp

In person session at the developers meeting

Conveners: Peter Peterson (Oak Ridge National Laboratory), Sarah Foxley (STFC)

09:00 Recap of previous day

Speaker: Sarah Foxley (STFC)

09:15 Code Camp

Attendees need to bring a laptop capable of making changes to Mantid or have access to a remote machine that can.

The exact topics for the code camps are dynamic and will be determined by the attendees during the meeting.

Speakers: Peter Peterson (Oak Ridge National Laboratory), Sarah Foxley (STFC)

12:00 → 13:00 Lunch

Badges required

13:00 → 14:35 Developers Meeting - Hybrid: Updates

In person session at the developers meeting with remote attendees (hybrid)

Convener: Sarah Foxley (STFC)

13:30 Autoreduction and Live Reduction using Mantid at ORNL

Speaker: Marie Backman (Oak Ridge National Laboratory)

13:45 Texture in Mantid

Demonstration and Discussion of the current state of play of texture reduction in mantid

Speaker: Andy Bridger (STFC)

14:15 Release notes in Mantid

Speaker: Gui Maciel Pereira (STFC)

14:35 → 15:05 Afternoon coffee

15:05 → 17:00 Developers Meeting - Hybrid: Updates (continued)

In person session at the developers meeting with remote attendees (hybrid)

Convener: Sarah Foxley (STFC)

15:05 Unwrapping NAPI

Most files used for neutron data in Mantid use the NeXus format (.nxs), which specifies a common file structure for neutron, X-ray, and muon scattering data. For many years, Mantid has relied on the NeXus API (NAPI) to handle all elements of reading and writing. However, NAPI development is no longer supported, and the API has not been updated in almost a decade. To move Mantid forward, we need to take ownership of our own file IO. Major work for releases 6.13 and 6.14 completely removed reliance on NAPI, building a new framework in HDF5 directly. This talk will cover the new system, caveats to maintaining it, and also mention the difficult process of phasing out highly prolific legacy code.

Speaker: Scott Boston (Oak Ridge National Laboratory)

15:20 Mantid in a Browser: a greener alternative to cloud servers?

Most major facilities using Mantid run data analysis servers for their users. In many cases these are cloud-based virtual machines (VMs) which are allocated to a single user. The specifications of these VMs are often defined by the most computationally expensive tasks required so in many simpler cases they are underused. Furthermore they are often idle as users are waiting for data or simply forget to shut down the VMs when they are done. The advantage of these systems is that users don't have to install any software or to download their data. This can also be achieved more efficiently with a file server (for the data) and a WebAssembly/Javascript app where the computations are carried on the user's own computer. In this presentation I show how the Mantid Framework can be compiled to WebAssembly (wasm)[1] and run in-browser using the Pyodide Python distribution. Some Mantid GUI interfaces were ported by using a wrapper layer which replaces qtpy with code which translates the PyQt/PySide calls to Javascript using the OS.js environment. This saves having to compile Qt and PySide to wasm (which is possible). The disadvantage of this approach is that it is limited to 4GB of memory as wasm is a 32-bit platform, but the target here is for less compute-intensive "first look" applications. The prototype implementation also does not support threading although this is possible with wasm. [1] https://github.com/mducle/micromantid

Speaker: Duc Le (STFC)

15:40 Data Handling for Mantid Consuming Workflows

A presentation detailing the methodology SNAPRed (https://github.com/neutrons/SNAPRed) used to approach handling of run data, its ancillary data objects, and how this interacts with the Mantid API.

Speaker: Michael Walsh

15:55 Dependency Management and Cybersecurity

Speaker: Peter Peterson (Oak Ridge National Laboratory)

16:15 Modernizing Scientific Software Documentation: From Qt Assistant to QtWebEngine in Mantid

Speaker: Darsh Dinger (Software Engineer at SNS (ORNL))

16:30 Beyond Conda: Pixi and the Future of Scientific Python Environment Management

Scientific software projects increasingly combine Python with C++, GPU toolkits, and other native dependencies, creating challenges for reproducibility, deployment, and cross-platform support. Traditional tools—Conda, Poetry, uv, Hatch, and PDM—address parts of this problem but leave gaps in speed, determinism, or multi-language integration. Pixi, a new environment manager built on Conda and conda-forge, combines multi-language package support with modern Rust-based performance and reproducibility features. It installs compiled libraries and compilers alongside Python packages, automatically maintains lockfiles, and ensures deterministic environments across Linux, macOS, and Windows. Pixi’s high-performance solver accelerates dependency resolution while unifying Conda and PyPI packages. For deployment, Pixi offers portable environment archives, lightweight single-binary installs, and official container support, simplifying CI/CD pipelines and reducing environment drift. Compared to alternatives, Pixi provides speed, reproducibility, and multi-language capabilities that make it especially suited for scientific and HPC workflows.

Speaker: Chen Zhang (Oak Ridge National Laboratory)

16:45 Close out

Speaker: Sarah Foxley (STFC)

Wednesday, 5 November

08:30 → 09:00 Coffee and networking

09:00 → 12:00 Developers Meeting - In Person: Code Camp

In person session at the developers meeting

Conveners: Peter Peterson (Oak Ridge National Laboratory), Sarah Foxley (STFC)

09:00 Recap of previous day

Speaker: Sarah Foxley (STFC)

09:15 Code Camp

12:00 → 13:00 Lunch

Badge required

13:00 → 15:00 Developers Meeting - Hybrid: Lightning Talks

In person session at the developers meeting with remote attendees (hybrid)

Convener: Sarah Foxley (STFC)

13:00 Lightening Talks

TBC

14:35 Exploring how LLMs could improve my work

Speaker: Oleksandr Koshchii (Forschungszentrum Juelich)

14:45 → 15:05 Afternoon coffee

15:05 → 17:10 Developers Meeting - Hybrid: Lightning Talks (continued) and Close out

In person session at the developers meeting with remote attendees (hybrid)

Conveners: Peter Peterson (Oak Ridge National Laboratory), Sarah Foxley (STFC)

15:05 Coderabbit: Worth using?

A 5 minute lightening talk

Speaker: Jose Borreguero Calvo (ORNL)

15:10 Discussion around using AI to develop Mantid

Following on from Oleksandr's LLM talk and Jose's Coderrabbitai talk we will open the floor to a general discussion on developers using AI as a tool for developing Mantid.

15:45 Lightening Talks

TBC

16:30 Close out

Speakers: Peter Peterson (Oak Ridge National Laboratory), Sarah Foxley (STFC)

Thursday, 6 November

10:00 → 12:15 User Meeting (Hybrid): Project Reports

User meeting

Convener: Stephen Cottrell (STFC)

10:00 Welcome

For the User Meeting

Speaker: Hannah Griffin (STFC)

10:05 Introduction

Speaker: Stephen Cottrell (STFC)

10:15 Mantid as a Project

Speaker: Toby Perring (STFC)

10:35 Technical Working Group Report

Speaker: Peter Peterson (Oak Ridge National Laboratory)

10:55 Discussion

Speakers: Anders Markvardsen (STFC), Peter Peterson (Oak Ridge National Laboratory), Stephen Cottrell (STFC)

11:05 Break

11:20 Future Role of the Science Working Group

Discussion session

Speaker: Anders Markvardsen (STFC)

11:30 Thoughts about the SWG from the chair

Speaker: Anna Sokolova (ACNS, ANSTO)

11:40 Future of the User Meeting

Part of the SWG discussion session

Speaker: Stephen Cottrell (STFC)

11:50 Discussion (Role of SWG)

Speaker: Anders Markvardsen (STFC)

12:00 Mantid Update from the ACNS

Speaker: Anna Sokolova (ACNS, ANSTO)

12:15 → 13:30 Lunch

In RAL restaurant with coffee in meeting room

13:30 → 14:45 User Meeting (Hybrid): Science Applications

User meeting

Convener: Stephen Cottrell (STFC)

13:30 Automation and/or Streaming of Mantid Data Treatments

Speakers: Duc Le (STFC), Samuel Jones (STFC)

13:50 Mantid Update from ISIS

Speaker: David Voneshen (STFC)

14:10 Texture Analysis (ISIS/PSI collaboration)

Speaker: Florencia Malamud (Paul Scherrer Institut)

14:25 Single Crystal Diffraction Analysis using Mantid

Speaker: Pascal Manuel (STFC)

14:35 Correcting spin leakage in ToF full polarisation analysis SANS experiments

Speaker: Diego Alba Venero (STFC)

14:45 → 15:00 Break

15:00 → 16:35 User Meeting (Hybrid): Science Applications (continued)

User meeting

15:00 Mantid Update from the SNS

Speaker: Jonathan taylor (Oak Ridge National Laboratory)

15:20 Mantid Update from the ILL

Speaker: Stephane ROLS (Institut Laue Langevin)

15:40 Mantid Update from the CSNS

Speaker: Rong Du (institute of high energy physics)

16:00 Mantid Update from the MLZ

Speaker: Oleksandr Koshchii (Forschungszentrum Juelich)

16:20 Closeout

Speakers: Anders Markvardsen (STFC), Stephen Cottrell (STFC)