Julia v1.9 Release Notes

New language features

Language changes

Compiler/Runtime improvements

Command-line option changes

In Linux and Windows, --threads=auto now tries to infer usable number of CPUs from the process affinity which is set typically in HPC and cloud environments ([#42340]).

Multi-threading changes

Build system changes

New library functions

New library features

Standard library changes

Package Manager

LinearAlgebra

We are now wholly reliant on libblastrampoline (LBT) for calling BLAS and LAPACK. OpenBLAS is shipped by default, but building the system image with other BLAS/LAPACK libraries is not supported. Instead, it is recommended that the LBT mechanism be used for swapping BLAS/LAPACK with vendor provided ones. ([#44360])

Markdown

Printf

Random

REPL

SparseArrays

Dates

Downloads

Statistics

Sockets

Tar

Distributed

The package environment (active project, LOAD_PATH, DEPOT_PATH) are now propagated when adding local workers (e.g. with addprocs(N::Int) or through the --procs=N command line flag) ([#43270]).
addprocs for local workers now accept the env keyword argument for passing environment variables to the workers processes. This was already supported for remote workers ([#43270]).

UUIDs

Mmap

DelimitedFiles

Deprecated or removed

External dependencies

Tooling Improvements