Twenty-four codes were added to the ASCL in November 2019:

ATHOS: A Tool for HOmogenizing Stellar parameters
ATLAS: Turning Dopplergram images into frequency shift measurements
CLUSTEREASY: Lattice simulator for evolving interacting scalar fields in an expanding universe on parallel computing clusters
comb: Spectral line data reduction and analysis package

FFTLog-and-beyond: Generalized FFTLog algorithm
frbpoppy: Fast radio burst population synthesis in Python
Fruitbat: Fast radio burst redshift estimation
HeatingRate: Radioactive heating rate and macronova (kilonova) light curve

HLattice: Scalar fields and gravity simulator for the early universe
IDG: Image Domain Gridding
LATTICEEASY: Lattice simulator for evolving interacting scalar fields in an expanding universe
MARTINI: Mock spatially resolved spectral line observations of simulated galaxies

miluphcuda: Smooth particle hydrodynamics code
MORDI: Massively-Overlapped Ring-Diagram Inversion
OpenSPH: Astrophysical SPH and N-body simulations and interactive visualization tools
OrbWeaver: Galaxy/(sub)halo orbital processing tool

PLAN: A Clump-finder for Planetesimal Formation Simulations
planetplanet: General photodynamical code for exoplanet light curves
PypeIt: Python spectroscopic data reduction pipeline
TreeFrog: Construct halo merger trees and compare halo catalogs

uvplot: Interferometric visibilities plotter
VELOCIraptor-STF: Six-dimensional Friends-of-Friends phase space halo finder
WhereWolf: Galaxy/(sub)Halo ghosting tool for N-body simulations
Zeltron: Explicit 3D relativistic electromagnetic Particle-In-Cell code

Twenty-two codes were added to the ASCL in October 2019:

a3cosmos-gas-evolution: Galaxy cold molecular gas evolution functions
ANNz2: Estimating photometric redshift and probability density functions using machine learning methods
AOtools: Adaptive optics modeling and analysis toolkit
AOTOOLS: Reduce IR images from Adaptive Optics
ChainConsumer: Corner plots, LaTeX tables and plotting walks

Cobaya: Bayesian analysis in cosmology
DM_phase: Algorithm for correcting dispersion of radio signals
E0102-VR: Virtual Reality application to visualize the optical ejecta in SNR 1E 0102.2-7219
ECLIPS3D: Linear wave and circulation calculations
EMERGE: Empirical ModEl for the foRmation of GalaxiEs

exoplanet: Probabilistic modeling of transit or radial velocity observations of exoplanets
GetDist: Monte Carlo sample analyzer
LEO-Py: Likelihood Estimation of Observational data with Python
MarsLux: Illumination Mars maps generator
MiSTree: Construct and analyze Minimum Spanning Tree graphs

OCD: O’Connell Effect Detector using push-pull learning
orbitize: Orbit-fitting for directly imaged objects
PEXO: Precise EXOplanetology
PINK: Parallelized rotation and flipping INvariant Kohonen maps
PreProFit: Pressure Profile Fitter for galaxy clusters in Python

qnm: Kerr quasinormal modes, separation constants, and spherical-spheroidal mixing coefficients calculator
TLS: Transit Least Squares

Fourteen codes were added to the ASCL in September 2019:

AREPO: Cosmological magnetohydrodynamical moving-mesh simulation code
Auto-multithresh: Automated masking for clean
ChempyMulti: Multi-star Bayesian inference with Chempy
CLOVER: Convolutional neural network spectra identifier and kinematics predictor
EBHLIGHT: General relativistic radiation magnetohydrodynamics with Monte Carlo transport

EPOS: Exoplanet Population Observation Simulator
fgivenx: Functional posterior plotter
HADES: Hexadecapolar Analysis for Dust Estimation in Simulations (of CMB B-mode thermal dust emission)
HISS: HI spectra stacker
MultiColorFits: Colorize and combine multiple fits images for visually aesthetic scientific plots

RascalC: Fast code for galaxy covariance matrix estimation
SecularMultiple: Hierarchical multiple system secular evolution model
TPI: Test Particle Integrator
WVTICs: SPH initial conditions using Weighted Voronoi Tesselations

Thirty-two codes were added to the ASCL in July 2019:

Astro-SCRAPPY: Speedy Cosmic Ray Annihilation Package in Python
astrodendro: Astronomical data dendrogram creator
beamconv: Cosmic microwave background detector data simulator
CMDPT: Color Magnitude Diagrams Plot Tool
Dewarp: Distortion removal and on-sky orientation solution for LBTI detectors

GaussPy: Python implementation of the Autonomous Gaussian Decomposition algorithm
GaussPy+: Gaussian decomposition package for emission line spectra
GIST: Galaxy IFU Spectroscopy Tool
healvis: Radio interferometric visibility simulator based on HEALpix maps
intensitypower: Spectrum multipoles modeler

MCRGNet: Morphological Classification of Radio Galaxy Network
MGB: Interactive spectral classification code
molly: 1D astronomical spectra analyzer
OMNICAL: Redundant calibration code for low frequency radio interferometers
Plonk: Smoothed particle hydrodynamics data analysis and visualization

POCS: PANOPTES Observatory Control System
PRISM: Probabilistic Regression Instrument for Simulating Models
pyGTC: Parameter covariance plots
pyuvdata: Pythonic interface to interferometric data sets
REVOLVER: REal-space VOid Locations from suVEy Reconstruction

ROHSA: Separation of diffuse sources in hyper-spectral data
RVSpecFit: Radial velocity and stellar atmospheric parameter fitting
SARA-PPD: Preconditioned primal-dual algorithm for radio-interferometric imaging
sbpy: Small-body planetary astronomy
schwimmbad: Parallel processing pools interface

Skyfield: High precision research-grade positions for planets and Earth satellites generator
SPAM: Hu-Sawicki f(R) gravity imprints search
StePar: Inferring stellar atmospheric parameters using the EW method
TurbuStat: Turbulence statistics in spectral-line data cubes
Wōtan: Stellar detrending methods

XDF-GAN: Mock astronomical survey generator
ZChecker: Zwicky Transient Facility moving target checker for short object lists

Twenty-two codes were added to the ASCL in June 2019:

Astroalign: Asterism-matching alignment of astronomical images
Blimpy: Breakthrough Listen I/O Methods for Python
centerRadon: Center determination code in stellar images
FREDDA: A fast, real-time engine for de-dispersing amplitudes
GPUVMEM: Maximum Entropy Method (MEM) GPU algorithm for radio astronomical image synthesis

Kalman: Forecasts and interpolations for ALMA calibrator variability
limb-darkening: Limb-darkening coefficients generator
Lizard: An extensible Cyclomatic Complexity Analyzer
LIZARD: Particle initial conditions for cosmological simulations
mcfit: Multiplicatively Convolutional Fast Integral Transforms

MEGAlib: Medium Energy Gamma-ray Astronomy library
MORPHEUS: A 3D Eulerian Godunov MPI-OpenMP hydrodynamics code with multiple grid geometries
Morpheus: Pixel-level analysis of astronomical image data
OIT: Nonconvex optimization approach to optical-interferometric imaging
PandExo: Instrument simulations for exoplanet observation planning

PlasmaPy: Core Python package for plasma physics
PyA: Python astronomy-related packages
pyLIMA: Microlensing modeling package
PyMORESANE: Python MOdel REconstruction by Synthesis-ANalysis Estimators
T-RECS: Tiered Radio Extragalactic Continuum Simulation

The Exo-Striker: Transit and radial velocity interactive fitting tool for orbital analysis and N-body simulations
turboSETI: Python-based SETI search algorithm

Twenty-seven codes were added to the ASCL in May, 2019:

Astrocut: Tools for creating cutouts of TESS images
Bandmerge: Merge data from different wavebands
beamModelTester: Model evaluation for fixed antenna phased array radio telescopes
Binospec: Data reduction pipeline for the Binospec imaging spectrograph
CASI-2D: Convolutional Approach to Shell Identification – 2D

ClusterPyXT: Galaxy cluster pipeline for X-ray temperature maps
evolstate: Assign simple evolutionary states to stars
FastPM: Scaling N-body Particle Mesh solver
Fermitools: Fermi Science Tools
Fitsverify: FITS file format-verification tool

Grizli: Grism redshift and line analysis software
HAOS-DIPER: HAO Spectral Diagnostic Package For Emitted Radiation
LensCNN: Gravitational lens detector
LensQuEst: CMB Lensing QUadratic Estimator
MMIRS-DRP: MMIRS Data Reduction Pipeline

NAPLES: Numerical Analysis of PLanetary EncounterS
ODEPACK: Ordinary differential equation solver library
PICASO: Planetary Intensity Code for Atmospheric Scattering Observations
Prospector: Stellar Population inference from spectra and SEDs
Py4CAtS: PYthon for Computational ATmospheric Spectroscopy

PyPDR: Chemistry, thermal balance, and molecular excitation code
Q3C: A PostgreSQL package for spatial queries and cross-matches of large astronomical catalogs
rPICARD: Radboud PIpeline for the Calibration of high Angular Resolution Data
SEDPY: Modules for storing and operating on astronomical source spectral energy distribution
SICON: Stokes Inversion based on COnvolutional Neural networks

SPARK: K-band Multi Object Spectrograph data reduction
THALASSA: Orbit propagator for near-Earth and cislunar space

Thirty codes were added to the ASCL in April, 2019:

AutoBayes: Automatic design of customized analysis algorithms and programs
CausticFrog: 1D Lagrangian Simulation Package
CDAWeb: Coordinated Data Analysis Web
CGS: Collisionless Galactic Simulator
CLEAR: CANDELS Ly-alpha Emission at Reionization processing pipeline and library

covdisc: Disconnected covariance of 2-point functions in large-scale structure of the Universe
deproject: Deprojection of two-dimensional annular X-ray spectra
dfitspy: A dfits/fitsort implementation in Python
digest2: NEO binary classifier
ehtim: Imaging, analysis, and simulation software for radio interferometry

EightBitTransit: Calculate light curves from pixel grids
eleanor: Extracted and systematics-corrected light curves for TESS-observed stars
FortesFit: Flexible spectral energy distribution modelling with a Bayesian backbone
GALAXY: N-body simulation software for isolated, collisionless stellar systems
JVarStar: Variable Star Analysis Library

nbodykit: Massively parallel, large-scale structure toolkit
nudec_BSM: Neutrino Decoupling Beyond the Standard Model
OoT: Out-of-Transit Light Curve Generator
Properimage: Image coaddition and subtraction
pyRSD: Accurate predictions for the clustering of galaxies in redshift-space in Python

rate: Reliable Analytic Thermochemical Equilibrium
repack: Repack and compress line-transition data
SARAH: SUSY and non-SUSY model builder and analyzer
SBGAT: Small Bodies Geophysical Analysis Tool
simuTrans: Gravity-darkened exoplanet transit simulator

SMILI: Sparse Modeling Imaging Library for Interferometry
Specstack: A simple spectral stacking tool
sxrbg: ROSAT X-Ray Background Tool
TP2VIS: Total Power Map to Visibilities
Vevacious: Global minima of one-loop effective potentials generator

Twelve codes were added to the ASCL in February, 2019:

dyPolyChord: Super fast dynamic nested sampling with PolyChord
ExPRES: Exoplanetary and Planetary Radio Emissions Simulator
GraviDy: Gravitational Dynamics
LiveData: Data reduction pipeline

LPNN: Limited Post-Newtonian N-body code for collisionless self-gravitating systems
PINT: High-precision pulsar timing analysis package
PyMF: Matched filtering techniques for astronomical images
Radynversion: Solar atmospheric properties during a solar flare

RPFITS: Routines for reading and writing RPFITS files
SNTD: Supernova Time Delays
Specutils: Spectroscopic analysis and reduction
SpecViz: 1D Spectral Visualization Tool

And sixteen codes were added to the ASCL in March, 2019:

allesfitter: Flexible star and exoplanet inference from photometry and radial velocity
AsPy: Aspherical fluctuations on the spherical collapse background
brutifus: A Python module to post-process datacubes from integral field spectrographs
DAVE: Discovery And Vetting of K2 Exoplanets

GalIMF: Galaxy-wide Initial Mass Function
Galmag: Computing realistic galactic magnetic fields
HelioPy: Heliospheric and planetary physics library
ICSF: Intensity Conserving Spectral Fitting

NFWdist: Density, distribution function, quantile function and random generation for the 3D NFW profile
NIFTy5: Numerical Information Field Theory v5
PLATON: PLanetary Atmospheric Transmission for Observer Noobs
PRF: Probabilistic Random Forest

SimSpin: Kinematic analysis of galaxy simulations
SIXTE: Simulation of X-ray Telescopes
SPICE: Observation Geometry System for Space Science Missions
SpiceyPy: Python wrapper for the NAIF C SPICE Toolkit

Twelve codes were added to the ASCL in January, 2019:

bettermoments: Line-of-sight velocity calculation
Bilby: Bayesian inference library
CCL: Core Cosmology Library
cFE: Core Flight Executive

eddy: Extracting Disk DYnamics
Galaxia_wrap: Galaxia wrapper for generating mock stellar surveys
OCFit: Python package for fitting of O-C diagrams
Photon: Python tool for data plotting

SEDobs: Observational spectral energy distribution simulation
ssos: Solar system objects detection pipeline
stellarWakes: Dark matter subhalo searches using stellar kinematic data
unwise_psf: PSF models for unWISE coadds