Red Hat Enterprise Linux 9.1 brings new features and enhancements that deliver a more secure and consistent foundation for open, hybrid cloud environments and allow organizations to deliver workloads, applications, and services faster and more efficiently. Red Hat Enterprise Linux 9.1 can be downloaded at no cost as a part of the Red Hat Developer Subscription for Individuals.

This article summarizes some of the ways Red Hat Enterprise Linux 9.1 further improves the developer experience.

The latest language runtimes and tools

Many of the most popular languages in enterprise and web development have seen upgrades.

  • Ruby 3.1 is a new release that includes a new experimental in-process just-in-time (JIT) compiler. The JIT achieves both a fast warmup time and performance improvements on most real-world software, producing up to a 22% performance improvement on railsbench and 39% on liquid-render. The new debugger improves performance, including multi-thread and multi-process debugging, without slowing down applications.
  • Maven 3.8 is a new version of the build automation tool used to build, publish, deploy, and manage projects, primarily in Java. To mitigate the risks of domain hijacking and man-in-the-middle (MITM) attacks, Maven 3.8 blocks HTTP access to external repositories, making HTTPS the default access protocol. This restriction adds an additional security layer for applications.
  • .NET 7 is the new version of .NET that brings many improvements in start-up and steady-state performance, as well as OpenTelemetry support. .NET 7, as a part of Red Hat Enterprise Linux 9.1, helps developers build cloud-native applications. With .NET 7, it is easier to modernize applications from legacy .NET versions.
  • Node.js 18 is a new version that includes an update of the V8 JavaScript engine, a global fetch enabled by default, and a core test runner module. Node.js 18 has launched an experimental fetch() API and Web Stream browser-compatible APIs for developers. Another available global API in Node.js 18 is BroadcastChannel, which is dedicated to cross-context communication between multiple tabs of the same origin.
  • PHP 8.1 is a major version update offering many new features, including enums, read-only properties, first-class callable syntax, fibers, intersection types, and performance improvements.

The latest versions of toolsets and compilers

Red Hat Enterprise Linux 9.1 is built with GCC 11.3 and offers updated versions of the LLVM (14.0.6), Rust (1.62.1), and Go (1.18.4) toolsets, enabling developers to modernize their applications with the latest compilers and toolsets.


Red Hat Enterprise Linux 9.1 comes with the new GCC Toolset version 12, which features the latest versions of development tools, with bug fixes and enhancements for Annobin and the GDB debugger. GCC 12 is available as an application stream in the form of a software collection in the AppStream repository and has critical bug fixes and enhancements that come from upstream GCC.


Red Hat Enterprise Linux 9.1 comes with LLVM toolset version 14.0, which comes with notable changes for x86 and ARM architectures:

  • Support for the Intel AVX-512 - FP16 instruction set on the x86_64 architecture.
  • More streamlined support for the latest ARMv9 64-bit architecture than previous versions.
  • Support for -Wdeclaration-after-statement with C99 and later standards, and not just C89, matching GCC's behavior. An important benefit is a support for style guides that forbid mixing declarations and code but want to move to newer C standards.

For more information on LLVM 14.0, refer to the LLVM 14.0.0 release notes.


Red Hat Enterprise Linux 9.1 comes with Rust 1.62, which has fixed issues related to the compiler and standard library. Notable enhancements in Rust 1.62 include:

  • Support for inline assembly on 64-bit x86 and 64-bit ARM using the core::arch::asm! macro.
  • A custom futex-based implementation in Mutex, CondVar, and RwLock instead of pthreads, with new optimizations made possible by Rust language guarantees.
  • Custom exit codes from main, including user-defined types that implement the newly-stabilized Termination trait.


Red Hat Enterprise Linux 9.1 comes with Go 1.18, which adds support for generic types. Go 1.18 includes bug and security fixes to the compiler and standard library. This includes changes in go get, go mod, go mod vendor, and go mod tidy, notably:

  • go get: Does not build or install packages in module-aware mode. Now this command handles only dependencies in go.mod.
  • go mod: Has enhancements in go mod download. It downloads source code only for modules explicitly required in the main module's go.mod file.
  • go mod tidy: Retains additional checksums in the go.sum file for modules whose source code is needed for the imported packages.

Enhancements for system automation and standardization

Automation and management capabilities in Red Hat Enterprise Linux 9.1 are provided by the Red Hat Enterprise Linux web console and Red Hat Enterprise Linux system roles. These capabilities help to automate manual tasks, standardize deployment, and provide ease of management in administrative activities.

Red Hat Enterprise Linux web console

Red Hat Enterprise Linux web console provides capabilities to view and manage cryptographic policies across systems, to make those systems consistent and protect them from future attacks. Users can edit firewall policies from the web console, including updating or changing port numbers and updating descriptions.

Red Hat Enterprise Linux system roles

Red Hat Enterprise Linux provides various system roles, including storage, firewall, network, and Microsoft SQL Server. Some of the benefits enabled by these system roles are:

  • Support for Always On availability: The Microsoft SQL Server system role introduces support for Always On availability groups, enabled through a Red Hat Enterprise Linux high availability add-on. The role can configure synchronous clusters (up to five nodes in SQL Server 2019) to scale read performance and includes support for configuration-only replicas that can reduce cluster licensing costs.
  • Support for thinly-provisioned volumes: Support in the storage system role includes adding and removing disks from storage pools, and the ability to create and attach cache volumes to existing volumes.
  • Support for network configurations: The network system role now supports network configurations using the NMState API, configuring policy-based routing, and configuring IP over Infiniband connections.

Downloads and more information

We suggest you check out the following sites:

Try out Red Hat Enterprise Linux 9.1 to deploy applications anywhere from bare metal to edge, and manage applications on a secure platform. Get insights to continuously analyze platforms and applications to predict risk and recommend actions.

Last updated: August 14, 2023