microsoft/BuildXL

Microsoft Build Accelerator

1,019

stars

6,492

commits

C#

primary language

Sep 11, 2026

updated

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README

BuildXL (Microsoft Build Accelerator)

BuildXL Icon

Introduction

BuildXL (Microsoft Build Accelerator) is a build engine originally developed for large internal teams at Microsoft. Internally at Microsoft, BuildXL runs 150,000+ builds per day on monorepo codebases up to a half-terabyte in size with a half-million process executions per build. It leverages distribution to thousands of data center machines and petabytes of source code, package, and build output caching. Thousands of developers use BuildXL on their desktops for faster builds.

BuildXL accelerates multiple build languages, including:

  • JavaScript
  • MSBuild
  • Ninja (CMake)
  • Its own internal scripting language, DScript, an experimental TypeScript based format used as an intermediate language by a small number of teams inside Microsoft

BuildXL has a command-line interface. There are currently no plans to integrate it into Visual Studio. The project is open source in the spirit of transparency of our engineering system. You may find our technology useful if you face similar issues of scale. Note that BuildXL is not intended as a replacement for MSBuild or to indicate any future direction of build languages from Microsoft.

OS compatibility:

  • Windows 10+
  • Ubuntu 22.04, 24.04
  • Azure Linux 3

Examples

See the Examples/ folder for basic project examples.

Documentation

The BuildXL documentation landing page is here and look at the developer guide in order to understand how to build and use BuildXL.

Build Status - Azure DevOps Pipelines

Build status

Contributors

(top 30 of 80)

smera

768 commits

mpysson

732 commits

SergeyTeplyakov

609 commits

marcelolynch

533 commits

microsoft/BuildXL

Microsoft Build Accelerator

1,019

stars

6,492

commits

C#

primary language

Sep 11, 2026

updated

cli
coreclr
filesystem
kernel
macos
netstandard
orchestration
sandbox
unix
xcode
xplat

README

BuildXL (Microsoft Build Accelerator)

BuildXL Icon

Introduction

BuildXL (Microsoft Build Accelerator) is a build engine originally developed for large internal teams at Microsoft. Internally at Microsoft, BuildXL runs 150,000+ builds per day on monorepo codebases up to a half-terabyte in size with a half-million process executions per build. It leverages distribution to thousands of data center machines and petabytes of source code, package, and build output caching. Thousands of developers use BuildXL on their desktops for faster builds.

BuildXL accelerates multiple build languages, including:

  • JavaScript
  • MSBuild
  • Ninja (CMake)
  • Its own internal scripting language, DScript, an experimental TypeScript based format used as an intermediate language by a small number of teams inside Microsoft

BuildXL has a command-line interface. There are currently no plans to integrate it into Visual Studio. The project is open source in the spirit of transparency of our engineering system. You may find our technology useful if you face similar issues of scale. Note that BuildXL is not intended as a replacement for MSBuild or to indicate any future direction of build languages from Microsoft.

OS compatibility:

  • Windows 10+
  • Ubuntu 22.04, 24.04
  • Azure Linux 3

Examples

See the Examples/ folder for basic project examples.

Documentation

The BuildXL documentation landing page is here and look at the developer guide in order to understand how to build and use BuildXL.

Build Status - Azure DevOps Pipelines

Build status

See what people are saying

Contributors

(top 30 of 80)

smera

768 commits

mpysson

732 commits

SergeyTeplyakov

609 commits

marcelolynch

533 commits

Languages

C#

83.4%

C

5.9%

TypeScript

5.5%

C++

3.2%

DenizenScript

1.3%