Welcoming Repositories Index Julia Ecosystem

Top Welcoming Open-Source Julia Repositories

Top welcoming Julia repositories. Scored by real 90-day external PR merge rates, maintainer review turnaround speed, and first-time contributor success.

Updated daily • Sun, 30 Aug 2026 UTC
Tracked Repos
901
>100 stars verified
Avg Merge Rate
91%
90-day external PRs
Open GFIs
18
Beginner friendly issues
Welcoming Tier
30
S & A Tier maintainers

Ranked Julia Repositories

Showing top 50 of 901 ranked repositories

RankRepositoryTierScoreMerge RateGood First Issues
#1
CPU/GPU portable array, parallel_for/parallel_reduce in Julia for productive science. Funded by the US DOE Advanced Scientific Computing Research (ASCR).
S•Elite75.989.9% -
#2
Utilities and abstractions for Machine Learning tasks
S•Elite75.0100.0% -
#3
Model and solve optimal control problems in Julia, both on CPU and GPU.
S•Elite74.892.7% -
#4
Evaluating Robustness of Neural Networks with Mixed Integer Programming
B•Solid73.993.0% -
#5
Julia debugger
S•Elite72.793.3% -
#6
An open source model predictive control and moving horizon estimation package for Julia
B•Solid72.490.7% -
#7
HTTP for Julia
S•Elite72.489.0% -
#8
An opinionated code formatter for Julia. Plot twist - the opinion is your own.
S•Elite72.089.8%4
#9
Neural Network primitives with multiple backends
S•Elite72.086.7% -
#10
Fast and automatic structural identifiability software for ODE systems
S•Elite71.787.1% -
#11
High-performance reactive message-passing based Bayesian inference engine
S•Elite71.392.9% -
#12
Reservoir computing utilities for scientific machine learning (SciML)
S•Elite70.781.0% -
#13
Symbolic programming for the next generation of numerical software
S•Elite70.287.2% -
#14
Documentation for the DiffEq differential equations and scientific machine learning (SciML) ecosystem
B•Solid70.286.1% -
#15
Interpreter for Julia code
A•Welcoming69.987.5% -
#16
Clapeyron provides a framework for the development and use of fluid-thermodynamic models, including SAFT, cubic, activity, multi-parameter, and COSMO-SAC.
A•Welcoming69.882.1%1
#17
Designs for new Base array interface primitives, used widely through scientific machine learning (SciML) and other organizations
B•Solid69.5100.0% -
#18
A Julia library of summation-by-parts (SBP) operators used in finite difference, Fourier pseudospectral, continuous Galerkin, and discontinuous Galerkin methods to get provably stable semidiscretizations, paying special attention to boundary conditions.
B•Solid69.3100.0% -
#19
LinearSolve.jl: High-Performance Unified Interface for Linear Solvers in Julia. Easily switch between factorization and Krylov methods, add preconditioners, and all in one interface.
A•Welcoming69.284.1% -
#20
The official registry of general Julia packages
A•Welcoming68.993.1% -
#21
Template for Julia Programming Language packages using the copier engine.
A•Welcoming68.996.8%1
#22
nextgen MLStyle: Generic Algebraic Data Type + Pattern Match
B•Solid68.6100.0%1
#23
Functions generated at runtime without world-age issues or overhead
B•Solid68.590.0% -
#24
Automatically update function definitions in a running Julia session
B•Solid68.394.9% -
#25
Read and write XML in pure Julia
B•Solid68.189.7% -
#26
An acausal modeling framework for automatically parallelized scientific machine learning (SciML) in Julia. A computer algebra system for integrated symbolics for physics-informed machine learning and automated transformations of differential equations
A•Welcoming67.786.4% -
#27
Julia package for tensor contractions and related operations
A•Welcoming67.690.3% -
#28
Solid state detector field and charge drift simulation in Julia
A•Welcoming67.490.9%1
#29
A Julia machine learning framework
B•Solid67.4100.0% -
#30
Quantum Toolbox in Julia
A•Welcoming67.286.3%1
#31
Mike's Little Intermediate Representation
B•Solid67.1100.0% -
#32
A package for binary and continuous, single and multi-material, truss and continuum, 2D and 3D topology optimization on unstructured meshes using automatic differentiation in Julia.
A•Welcoming66.880.9% -
#33
A new language server for Julia, enabling modern, compiler-powered tooling.
A•Welcoming66.797.2% -
#34
Solution of nonlinear multiphysics partial differential equation systems using the Voronoi finite volume method
B•Solid66.5100.0% -
#35
A differentiable simulator for scientific machine learning (SciML) with N-body problems, including astrophysical and molecular dynamics
B•Solid66.4100.0% -
#36
Static Code Analysis for Julia
B•Solid66.0100.0% -
#37
A Julia package to construct orthogonal polynomials, their quadrature rules, and use it with polynomial chaos expansions.
B•Solid65.995.5% -
#38
Lightweight and easy generation of quasi-Monte Carlo sequences with a ton of different methods on one API for easy parameter exploration in scientific machine learning (SciML)
A•Welcoming65.888.9% -
#39
SparseArrays.jl is a Julia stdlib for working with sparse matrices
A•Welcoming65.889.6% -
#40
SymbolicNumericIntegration.jl: Symbolic-Numerics for Solving Integrals
B•Solid65.795.8% -
#41
Implementation of a language-level autograd compiler
A•Welcoming65.683.3% -
#42
Collection of fundamental physical constants with uncertainties. It supports arbitrary-precision constants
B•Solid65.3100.0% -
#43
Exploratory analysis of Bayesian models with Julia
B•Solid65.2100.0% -
#44
Functional reactive programming extensions library for Julia
B•Solid65.0100.0% -
#45
An interface to various automatic differentiation backends in Julia.
A•Welcoming64.982.1% -
#46
Taylor polynomial expansions in one and several independent variables.
A•Welcoming64.988.9% -
#47
High performance ordinary differential equation (ODE) and differential-algebraic equation (DAE) solvers, including neural ordinary differential equations (neural ODEs) and scientific machine learning (SciML)
A•Welcoming64.777.4% -
#48
A standard library of components to model the world and beyond
B•Solid64.784.9% -
#49
Finite element toolbox for Julia
A•Welcoming64.671.3%9
#50
Physics-Informed Neural Networks (PINN) Solvers of (Partial) Differential Equations for Scientific Machine Learning (SciML) accelerated simulation
A•Welcoming64.381.3% -

How to Get Your Julia PR Merged

1
Check C-Rankâ„¢ First: Pick projects with S or A tiers to avoid maintainer ghosts and slow review cycles.
2
Run Local Verification: Ensure test suites and formatting linters pass before opening a pull request.
3
Submit in Maintainer Windows: Check the repository report card to submit when maintainers are most active.

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Frequently Asked Questions: Julia Open Source

What is the most welcoming Julia open-source repository?

The highest-ranked Julia repository on GetMerged is currently JuliaGPU/JACC.jl, with a C-Rank score of 75.9/100 and a 89.9% PR merge rate.

How can I find good first issues in Julia?

You can browse verified beginner-friendly issues in Julia by visiting our curated Good First Issues directory at getmerged.abhishekco.de/good-first-issue/julia.

What makes a Julia repository ‘Super Welcoming’ on GetMerged?

A ‘Super Welcoming’ (S-Tier) Julia repository demonstrates an external PR merge rate above 80%, a median first response time within 24 to 48 hours, active review feedback, and clear onboarding documentation.