Modia.jl

If you intend to explore OpenModelica you may also like ModelingToolkit.jl: https://docs.sciml.ai/ModelingToolkit/dev/ There is also a project by Hilding Elmqvist, who worked for Dassault on Dymola (the leading commercial implementation of Modelica). His project is Modia.jl: https://github.com/ModiaSim/Modia.jl I can personally feel the Julia community settling on MTK, but Modia was ahead in the early stages of dynamic system simulation in Julia, and I believe MTK has drawn a lot of inspiration from each Modia and Modelica. Modia is a bit more ergonomic while also being the first to integrating things like 3D viewers and a complete multibody package by years, with Julia Computing only now catching up [1]. MTK has a better support for back-end solvers and holds a lot of promise to leapfrog Modia, especially since the release cadence for Mo

For circuits a lot of them are represented by differential-algebraic equations (DAEs) and require modeling tools in order to handle the high differential index of the systems. This is the reason why they are typically handled via acausal modeling systems which can do index reduction. For Julia, this is the ModelingToolkit portion of the SciML ecosystem (https://docs.sciml.ai/ModelingToolkit/stable/), and some modeling tools like https://github.com/ModiaSim/Modia.jl and OpenModelica front-ends https://github.com/OpenModelica/OMJulia.jl.

The creators of Modelica, Hilding Elmqvist and Martin Otter, work in Julia these days so there's been a boom to the development of acausal modeling tooling in Julia. They built https://github.com/ModiaSim/Modia.jl and then we collaborated with them on some ideas to build ModelingToolkit.jl (https://docs.sciml.ai/ModelingToolkit/dev/). The latest versions and experiments in OpenModelica are now targeting ModelingToolkit as a compilation backend, which gives a pathway for legacy Modelica code to be used with the MTK ecosystem. The OpenModelica community has always been a very small group in comparison to the Dymola compiler team and so the open part of Modelica never really caught on, but we hope to help them piggyback off of our compiler to get it there. We'll have a workshop on this collaboration in Linköping next February if you're inter

The thing to watch in the space of Simulink/Modelica is https://github.com/SciML/ModelingToolkit.jl . It's an acausal modeling system similar to Modelica (though extended to things like SDEs, PDEs, and nonlinear optimization), and has a standard library (https://github.com/SciML/ModelingToolkitStandardLibrary.jl) similar to the MSL. There's still a lot to do, but it's pretty functional at this point. The two other projects to watch are FunctionalModels.jl (https://github.com/tshort/FunctionalModels.jl, which is the renamed Sims.jl), which is built using ModelingToolkit.jl and puts a more functional interface on it. Then there's Modia.jl (https://github.com/ModiaSim/Modia.jl) which had a complete rewrite not too long ago, and in its new form it's fairly similar to ModelingToolkit.jl and the differences are more in the details. For causal m

Maybe of interest in that context: https://github.com/ModiaSim/Modia.jl The authors of that tool have a strong background in modeling and simulation of differential algebraic equations. Not so much in designing DSLs, though, so there maybe some technical oddities. But I expect the simulation aspect to be quite decent.

The two main contributors are just busy in their "real" jobs. https://github.com/ModiaSim/Modia.jl/graphs/contributors

There's a project to create a language similar to Modelica as a DSL in Julia, Modia[1]. I'm not currently a user of either language, but saw a presentation at JuliaCon about it[2] and thought it looked interesting. [1] https://github.com/ModiaSim/Modia.jl [2] https://youtu.be/hVg1eL1Qkws

For simulation there is also a library that reimplements the Modelica language in Julia using macros: https://github.com/ModiaSim/Modia.jl

Julia's meta-programming functionality is ideal for implementing such domain-specific languages (the popular JuMP suite is a flagship example in a different domain: https://jump.readthedocs.io/en/latest/). Several groups are working on systems inspired by Modelica, including: http://tshort.github.io/Sims.jl/latest/ and https://www.modelica.org/events/modelica2017/proceedings/htm... (https://github.com/ModiaSim/Modia.jl)