Free Software Activities in November 2018


Welcome to another of my monthly summaries on my work in the free software world. My mission is to make engineering and science available for everyone, and Debian, the Universal Operating System, is my weapon of choice.

I received some feedback on my last post that I made it seem I would be stepping away from my role maintaining FreeCAD and other packages on the Debian Science Team, which was an unfortunate miscommunication on my part. Mainly, I just would like to reduce the proportion of my overall free software time on it, from its current amount, nearly 100%, to a roughly even 1/3rd split between Debian Science, FreeCAD, and PostCAD. The latter is a promising personal project to make an OpenCASCADE-powered CAD extension for PostgreSQL, bringing support for CAD file formats, datatypes, and algorithms to the powerful Postgres ecosystem, similar to what PostCAD has done for geospatial analysis. This could serve as a backend for both FreeCAD in the short term, and in the long term, it could power a web-based version of FreeCAD, perhaps with some Django-powered middleware serving a REST API for some WebGL-based frontend.

So, besides summarizing my work this month, I also plan to give a synopsis on my Debian packaging, for both what's in-progress and on my wishlist. As you'll see, it's quite extensive. My hope is that by whittling away at both lists, my Debian Science work can focus more on maintenance of existing packages, and free up some time for other things.


My work on Debian Science, FreeCAD, and PostCAD is supported by my patrons on Patreon <>. While I had created a Liberapay a while back, I never got any traction with it, and I found out recently that it was because I had not set it up to actually receive payments. So, if you don't like Patreon for whatever reason, you can also support me on Liberapay. Just to round things out, if you don't like either of those platforms, you can also help support my work via PayPal.

Transition for coin3

Coin3D is a scene graph library and a fundamental part of FreeCAD. Unfortunately, it hasn't had a release since 2011, but development has been picking up recently, so it's likely that a release is not too far off. Even without a formal release, several improvements have been made including CMake support, so it's time to prepare a transition in advance of the Debian 10 release. Luckily, Leo Palomo-Avellaneda has taken the initiative of getting this transition started.

Currently, the new Coin3D package is available in Debian Experimental as we prepare the reverse-dependencies to build against it. For FreeCAD, we directly depend on Pivy, which are Python bindings for Coin. Pivy, in turn, depends on Coin and SoQt, which is a Qt GUI component toolkit library for Coin. A pre-release version of SoQt is also being packaged since, like Coin, CMake support has been added, as well as support for Qt 5.

Unfortunately, I've been grinding my gears on building Pivy against the new Coin and SoQt for a good part of this month, which is especially troublesome since FreeCAD's transition to Python 3 is blocked by the upload of a new Pivy, which I prepared earlier this year.

With any luck, I'll be able to help Leo finish the Coin and SoQt transition and have Pivy prepared in December.

Gmsh Update

Gmsh is a 3D finite element mesh generator with built-in pre- and post-processing facilities. It's also one of the main meshers used by FreeCAD's Finite Element Modeling Workbench, besides Netgen.

Currently Debian has Gmsh 3.0.6, but a new major version was released in August. I've already prepared this new major version for testing in FreeCAD's Community Extras PPA, but I hadn't cleaned up the packaging yet to submit to Debian. However, in November, there were two point releases, 4.0.5 and 4.0.6, so I wasn't able to complete this work this month, but I'm sure it'll be done in early December.

One major piece of information regarding Gmsh 4 is a change in the API: the libjava-gmsh3 package in Debian was never meant to be a public API, and so Gmsh upstream has requested that we no longer ship it. To offset this, there have been refinements for the actual public API, which officially comes in C, Python 3 and (new) Julia flavors. However, I haven't found much information on Julia packaging in Debian, so I'll likely hold off on that package.

PySide 2 Rebuild & PPA Plans

Since FreeCAD is an LGPL-licensed Qt project, we must use PySide and not PyQt to do Qt things with Python. Because of this, the FreeCAD migration to Qt 5 on Debian was blocked by the packaging of PySide 2, which was completed by Freexian SARL over the summer. In Debian, we now have a Qt 5-enabled FreeCAD, although our daily builds PPA is still using Qt 4.

Besides the Qt 4->5 transition, we're also finishing up a Python 2->3 transition. At the end of the summer I published a freecad-python3 package in the PPA which also used Qt 5. However, it wasn't really fully usable, moreso a proof-of-concept that such a build indeed buildable.

At this point, the Debian FreeCAD package has begun to diverge from the FreeCAD PPAs; besides Qt 5 builds not being available currently, the Debian package has also been split into several packages (e.g. libfreecad, freecad-common, etc. packages) in order to better comply with Debian Policy and the Filesystem Hierarchy Standard.

So, there's a bit of work to do to catch the PPAs up. First, the package split needs to be done. Then, I need to upload an alternative freecad-daily package for Qt 5 builds, separate from Python 3. Once that is done and has undergone some testing, freecad-daily can be replaced by it, and it in turn can be replaced by a freecad-python3 package for further testing. Since FreeCAD's 0.18 release is imminent, I'll need to get this taken care of during December, so stay tuned.

Packaging in Progress

My first packaging list is all the software I've already started packaging. For some, it's almost complete, and for others, I've only just begun.

The purpose of these lists is not to give status updates, but to announce what all I'm interested in to anyone reading this, and to give an idea of how much packaging work I have in mind to improve this usage of Debian.


Homepage, GitHub

Cantera is an open-source suite of tools for problems involving chemical kinetics, thermodynamics, and transport processes.

I had this package working and waiting to be sponsored, but it looks like it currently fails to build from source, so this just requires some maintenance.


Homepage, GitHub

CoolProp is a thermophysical property database and wrappers for a selection of programming environments. It offers similar functionality to REFPROP, although CoolProp is open-source and free.

This package was previously building completely, but failing when one would attempt to do an import coolprop. Now that it's been a while since I worked with it, it seems to be failing to build.


Homepage, GitHub

Elmer is a finite element software for numerical solution of partial differential equations. Elmer is capable of handling any number of equations and is therefore ideally suited for the simulation of multiphysical problems. It includes models, for example, of structural mechanics, fluid dynamics, heat transfer and electromagnetics. Users can also write their own equations that can be dynamically linked with the main program.

This was previously in Debian but removed due to abandonment, so a great deal of the work is already done, but it also requires quite a bit of updating to current Debian standards.


PDF Standard, GitHub

Open-source C++ implementation of the IAPWS-IF97 equations to calculate properties of the pure water substance.

This is a dependency of CoolProp, and I already have it packaged and waiting for sponsorship at


Homepage, GitHub

IfcOpenShell is an open source (LGPL) software library that helps users and software developers to work with the IFC file format. The IFC file format can be used to describe building and construction data. The format is commonly used for Building Information Modelling. IfcOpenShell uses OpenCASCADE internally to convert the implicit geometry in IFC files into explicit geometry that any software CAD or modelling package can understand.

I already have this packaged and awaiting sponsorship at

It's also available on the FreeCAD Community Extras PPA.


Homepage, GitHub

IfcPlusPlus is an open source C++ class model, as well as a reader and writer for IFC files in STEP format. It features easy and efficient memory management using smart pointers, a parallel reader for fast parsing on multi-core CPU's, and a simple IFC viewer application using Qt and OpenSceneGraph.

I already have this packaged and awaiting sponsorship at

It's also available on the FreeCAD Community Extras PPA.


Homepage, GitHub

OpenCAMLib (OCL) is a C++ library with Python bindings for creating 3D toolpaths for CNC-machines such as mills and lathes.

I already have this packaged and awaiting sponsorship at

It's also available on the FreeCAD Community Extras PPA.


Homepage, GitHub

2D voronoi diagram for point and line-segment sites using incremental topology-oriented algorithm. C++ with Python bindings.

I already have this packaged and awaiting sponsorship at

It's also available on the FreeCAD Community Extras PPA.


Homepage, GitHub

C++ library for multi-physics simulation. The applications areas in which Chrono is most often used are vehicle dynamics, robotics, and machine design. In vehicle dynamics, Chrono has mature support for tire/terrain interaction modeling and simulation.

I've only roughly begun packaging this, and I'm already tired of typing libprojectchrono. Anyway, it's a rather large set of components which will be broken up into several packages. Luckily, things are done in a pretty normal way so I don't imagine this will be difficult to finish packaging, just a little time-costly.



A stand-alone library of the mesh framework from the Salome Platform

I've gotten this standalone version of SMESH packaged and awaiting sponsorship at Eventually, I want to package the entire Salome Platform, but it's extremely large and really several source packages. Packaging this as an intermediate step allows us to remove SMESH from FreeCAD's included sources.

It's also available on the FreeCAD Community Extras PPA.


Homepage, GitHub

XC is an open source FEA program designed to solve structural analysis problems.

This library is supposed to be an alternative to the not-quite-freely licensed OpenSees, which is used in seismic research and analysis. There has been some interest in the FreeCAD forums about using this, so I'm beginning packaging it in advance. However, it seems a bit complicated as it requires multiple sources, the GitHub xcfem/xc repo as well as xcfem/xc_utils.

Wishlist Packages


Homepage, GitLab

lib2geom (2Geom in private life) was initially a library developed for Inkscape but will provide a robust computational geometry framework for any application. It is not a rendering library, instead concentrating on high level algorithms such as computing arc length.

I looked at this package and it seemed like it will be straightforward to package, and with the parent project's popularity, someone else may get to it first.


Homepage, GitHub

The Building Information Model server (short: BIMserver) enables you to store and manage the information of a construction (or other building related) project. Data is stored in the open standard IFC. The BIMserver is not a fileserver, but it uses a model-driven architecture approach. This means that IFC data is stored in an underlying database. The main advantage of this approach is the ability to query, merge and filter the BIM-model and generate IFC files on the fly.

The integration of BIM with FreeCAD is a very promising endeavor, and letting FreeCAD be the client in a client-server model provides many potential benefits. (This is the reason I'm working on PostCAD.) Packaging BIMserver is a natural decision, then. However, it's a Java application, which I have little experience with language-wise and none in terms of packaging it in Debian, so this one has a bit of a difficulty associated with it.


Homepage, GitHub

CadQuery is an intuitive, easy-to-use python based language for building parametric 3D CAD models. CadQuery is for 3D CAD what jQuery is for javascript. Imagine selecting Faces of a 3d object the same way you select DOM objects with JQuery!

CadQuery is an interesting project which actually makes use of FreeCAD, and indeed FreeCAD even has a CadQuery Workbench. This would be nice to package as a way of extending the FreeCAD ecosystem on Debian.

Unfortunately, CadQuery 2 is planning on moving away from FreeCAD to PythonOCC, which is based on the now behind-the-times OpenCASCADE Community Edition fork, based on OpenCASCADE 6.9.1; FreeCAD and other projects are moving back to the mainline OpenCASCADE Technology project which is about to release version 7.4.0. It would be nice if both CadQuery and FreeCAD could instead move to use PyOCCT as a middle-layer between itself and OpenCASCADE.


Homepage, GitHub

This extension highlights the code snippets for over 350 languages in LibreOffice.

I have packaged a LibreOffice extension before, and it was fairly easy, so I expect this one will be too. However its priority is rather low.


Homepage, GitHub

Lib3MF is a C++ implementation of the 3D Manufacturing Format file standard.

This seems like a straightforward library to package, but there is no pressing need as FreeCAD does not support it yet.


Homepage, BitBucket

MUESLI, a Material UnivErSal LIbrary, is a collection of C++ classes and functions designed to model material behavior at the continuum level. Developed at IMDEA Materials, it is available to the material science and computational mechanics community as a suite of standard models and as a platform for developing new ones.

This seems like a great candidate package for Debian Science but I have had some difficulty building it, which I need to conquer before packaging can begin.


Homepage, GitHub

Cling is an interactive C++ interpreter, built on top of Clang and LLVM compiler infrastructure. Cling realizes the read-eval-print loop (REPL) concept, in order to leverage rapid application development. Implemented as a small extension to LLVM and Clang, the interpreter reuses their strengths such as the praised concise and expressive compiler diagnostics.

cling is an incredible project which should have been packaged already. Hopefully someone else gets to it first.



A command line tool which lists the licenses of all installed packages in a Debian-based system (like Ubuntu)

This is a small script which gives a summary of the licenses used by the installed packages on your system--a good way to audit packages, e.g. forbidding AGPL.


Homepage, GitHub

Landlab is a Python-based modeling environment that allows scientists and students to build numerical landscape models. Designed for disciplines that quantify earth surface dynamics such as geomorphology, hydrology, glaciology, and stratigraphy, it can also be used in related fields.

Landlab provides components to compute flows (such as water, sediment, glacial ice, volcanic material, or landslide debris) across a gridded terrain. With its robust, reusable components, Landlab allows scientists to quickly build landscape model experiments and compute mass balance across scales.

Landlab is another interesting Debian Science candidate but I have no pressing need to package it.


Homepage, GitHub

A static website and blog generator, written in Python.

Nikola is what I use to create this blog, but it's somewhat fast moving and a slow maintainer in Debian previously caused problems, so I don't want to pick this up until I've leveled up my package maintenance.


Homepage, GitHub

In some European countries, CAD projects must have font which conform to IS0 3O98 specification. Commercial CADs has this font, but free CADs not. There is no available free font yet, so this project will fix this. This font will be created completely from the scratch. Font is created with free tools like FontForge, Inkscape, Gimp. Font is available under 3 licences: GNU GPL licence version 3 with GPL font exception, GNU GPL licence version 2 with GPL font exception, GNU LGPL licence version 3 with GPL font exception.

This is a bundled font with FreeCAD, so I'd like to separate into its own package. However, the need to package it is not pressing, so I haven't picked it up.


Homepage, GitHub

pigpio is a C library for the Raspberry which allows control of the General Purpose Input Outputs (GPIO).

This is an important tool for teaching with Raspberry Pi's and should be packaged as soon as possible, I've just had more pressing concerns.


Homepage, GitHub

A logic analyser (digital waveform viewer). piscope uses the services of the pigpio library. pigpio needs to be running on the Pi whose gpios are to be monitored.

Being able to see the waveform of a GPIO pin on a Raspberry Pi is incredibly useful for teaching robotics and electrical engineering classes with them. This also needs to be packaged.



The pyOCCT project provides Python bindings to the OpenCASCADE 7.2.0 geometry kernel and SMESH 8.3.0 meshing library via pybind11. Together, this technology stack enables rapid CAD/CAE application development in the popular Python programming language.

This is a very promising library for Python OpenCASCADE development, so I'd like to get it packaged, but it's blocked by getting SMESH packaged.



A 3D rendering library written completely in Python.

A promising library for integrating raytracing functionality directly into FreeCAD, and for general raytracing in Python.



Quarter is a light-weight glue library that provides seamless integration between the Coin high-level 3D visualization library and Qt's 2D user interface library. The functionality in Quarter revolves around QuarterWidget, a subclass of QGLWidget. This widget provides functionality for rendering of Coin scenegraphs and translation of QEvents into SoEvents. Using this widget is as easy as using any other QWidget.

FreeCAD already uses an included (and slightly modified) copy of Quarter in its source, so I'd like to package Quarter in a standalone fashion as part of moving FreeCAD away from bundled copies in its source.


Homepage, GitHub

REBOUND is an N-body integrator, i.e. a software package that can integrate the motion of particles under the influence of gravity. The particles can represent stars, planets, moons, ring or dust particles. REBOUND is very flexible and can be customized to accurately and efficiently solve many problems in astrophysics.

This seems like a really great library to have in Debian Science, but it's not a priority.



SQLint is a simple command-line linter which reads your SQL files and reports any syntax errors or warnings it finds.

At this stage, SQLint checks SQL against the ANSI syntax, and uses the PostgreSQL SQL parser to achieve this. In time, we hope to add support for non-standard SQL variants (e.g. MySQL). Contributions are welcome.

This would be a very useful utility to have in Debian, but I always write SQL without flaw the first try. (wink)


Homepage, GitHub

The Soil & Water Assessment Tool is a small watershed to river basin-scale model used to simulate the quality and quantity of surface and ground water and predict the environmental impact of land use, land management practices, and climate change. SWAT is widely used in assessing soil erosion prevention and control, non-point source pollution control and regional management in watersheds.

SWAT is a powerful research tool in agricultural engineering, among several others I'm interested in eventually packaging for Debian. The planned package will be based on a CMake-enabled fork of the upstream source, which is built with Intel's Fortran compiler by default and also had to be adapted for gfortran.


Homepage, GitHub

Self hosted FLOSS fitness/workout and weight tracker written with Django

This is a very promising application which could be used as both a fitness tracker as well as a weight/nutrition tracker, something along the lines of a self-hosted MyFitnessPal. However, my other packaging priorities outweigh this at the moment.


So, there you have it! My mostly complete list of in-progress and wishlist items for Debian packaging. If you have any feedback on packages on the list, or want to get in touch with me, you can find me on Twitter or send me an email at kurt at I'll also be starting to stream my Debian & FreeCAD work very soon, subscribe to me on Twitch to get notified when I go live.


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