Active open source projects which use SCons as their build system.
Aria Maestosa - a C++ MIDI editor and composition/notation application
Bombono DVD authoring program with nice and clean GUI.
Cantera A toolkit for chemical kinetics and thermodynamics. Uses SCons for building a C++ library, Python packages, a Matlab toolbox, and Windows installers.
Consodoc (XML publishing server).
FreeNOS - a microkernel operating system written in C++.
FSP Project (File transfer protocol)
IntensityEngine An open source platform for 3D games and virtual worlds.
Hydrogen - advanced drum machine for GNU/Linux
LProf - ICC Profile creation application for color managing your imaging devices.
Madagascar (geophysical data processing and reproducible numerical experiments) Uses SCons not only for compiling software but also for managing data processing flows. See Main SConstruct, Reproducible computational experiments using SCons, Example SConstruct for signal processing.
Mapnik A Free Toolkit for developing mapping applications.
Mixxx - Free MP3 DJ Mixing Software
Nsound - C++ Audio Synthesis Framework
Palabos - Open-source CFD solver based on the lattice Boltzmann method.
PowderToy - Create a landscape in this physics sandbox engine...and then blow it up!
PowerScribe3000 - CD and DVD discs indexer.
Second Life Viewer - Client software for the Second Life 3D virtual world
Ubitrack Tracking for Mixed-/Augmented Reality applications, Chair for Computer Aided Medical Procedures and Augmented Reality, Technical University Munich
YafaRay A free open-source raytracing engine.
Less active projects, which use SCons as their build system:
Spook (X11 window manager) This project has disappeared almost without trace.
kio-clucene (flexible local search kio-slave for KDE) There appears to be no activity since 2005.
Rekall (KDE database frontend)
Projects which previously used SCons as their build system:
Delta3D Open source gaming and simulations engine, switched to CMake
Non Open source projects which use SCons as their build system.
ISTS TCP BIOS A proprietary loader software for a telecomunications traffic simulator
Battlefield 1942 (FPS and vehicle action game)
Nuance uses SBuild, a drop-in add-on to SCons-local, since January 2005. SBuild is not open source (yet).
http://www.doom3.com iD Software's Doom 3 SDK includes the internally used Scons files.
COPS 2170: The Power of Law (cyberpunk style tactical strategy with RPG elements)
ALFA: Antiterror (tactical simulation)
Pin (Binary Instrumentation Tool)
On 2008-02-17, Mark Brown scanned the packages in the Debian distribution for packages that used SCons. There may be some false positives due to the nature of the scan, but he found 35 packages. Many of them don't seem to be listed above. If someone has some spare cycles, tracking down the projects missing above and adding them would be a good thing. Here's the list: abakus aqsis ardour balder2d belpic blender blockattack btanks cheesetracker codeine create-resources csstidy darcs-buildpackage dc-qt dfsbuild gaia gtkrsync hg-buildpackage hpodder jppy kstreamripper linuxdcpp lprof mixxx nsis oregano pingus pouetchess pyexiv2 rafkill skim telepathy-inspector tla-buildpackage wlassistant yafray