FASTBuild vs Qbs

FASTBuild is an open-source build system for compiling software across Linux, macOS and Windows. It runs compilation work across worker threads, can reuse results from local or network caches, and can distribute builds among networked machines when their settings and worker setup are compatible. The maker says caching can accelerate compile times up to 10x. Some compiler settings do not support caching or distribution; FASTBuild handles affected objects without caching or builds them locally. Supported toolchains include MSVC, GCC, SNC, Clang, GreenHills, CodeWarrior and NVCC, plus syntactically compatible command-line compilers. It can combine C++ files into Unity or Blob builds, while allowing writable files to be built individually for quicker iteration. FASTBuild can generate Visual Studio and XCode project files. The maker describes it as a self-contained executable that needs no installation or dependencies beyond compiler tools. It is free, with commercial use and redistribution allowed under license conditions; the license provides the software without warranty. The listed current release is v1.20, released 26-Apr-2026.

Qbs is a build automation tool for managing software projects across multiple platforms. Projects can use it regardless of programming language, toolkit, or libraries, and its declarative model lets them describe build tasks and dependencies without setting the build order. The manual lists correct, fast incremental builds and an extensible architecture among its features. Qbs documents built-in support for Windows, Linux, macOS, Android, iOS, tvOS, watchOS, QNX, and FreeBSD, plus cross-compilation. It can be used with Qt Creator and Visual Studio Code through the Qbs session feature, and it can generate Clang compilation databases. Project generation for Visual Studio, IAR Embedded Workbench, and Keil uVision is available but described as experimental. Binaries are available for Windows, macOS, Linux, and FreeBSD, or Qbs can be built locally from source. The Qbs plan costs nothing. Its library and tools are available under commercial licenses, LGPL version 3, and GPL version 2. The Makefile generator will not create a Makefile if the source, build, or install root directory contains spaces; other UNIX-like systems may work but are not regularly tested or officially supported.