Thank you for taking the time to read about &SCons;.
&SCons; is a next-generation
software construction tool,
or make tool--that is, a software utility
for building software (or other files)
and keeping built software up-to-date
whenever the underlying input files change.
The most distinctive thing about &SCons;
is that its configuration files are
actually scripts,
written in the &Python; programming language.
This is in contrast to most alternative build tools,
which typically invent a new language to
configure the build.
&SCons; still has a learning curve, of course,
because you have to know what functions to call
to set up your build properly,
but the underlying syntax used should be familiar
to anyone who has ever looked at a Python script.
Paradoxically,
using Python as the configuration file format
makes &SCons;
easier
for non-programmers to learn
than the cryptic languages of other build tools,
which are usually invented by programmers for other programmers.
This is in no small part due to the
consistency and readability that are built in to Python.
It just so happens that making a real, live
scripting language the basis for the
configuration files
makes it a snap for more accomplished programmers
to do more complicated things with builds,
as necessary.
&SCons; Principles
There are a few overriding principles
we try to live up to in designing and implementing &SCons;:
Correctness
First and foremost,
by default, &SCons; guarantees a correct build
even if it means sacrificing performance a little.
We strive to guarantee the build is correct
regardless of how the software being built is structured,
how it may have been written,
or how unusual the tools are that build it.
Performance
Given that the build is correct,
we try to make &SCons; build software
as quickly as possible.
In particular, wherever we may have needed to slow
down the default &SCons; behavior to guarantee a correct build,
we also try to make it easy to speed up &SCons;
through optimization options that let you trade off
guaranteed correctness in all end cases for
a speedier build in the usual cases.
Convenience
&SCons; tries to do as much for you out of the box as reasonable,
including detecting the right tools on your system
and using them correctly to build the software.
In a nutshell, we try hard to make &SCons; just
"do the right thing" and build software correctly,
with a minimum of hassles.
Acknowledgements
&SCons; would not exist without a lot of help
from a lot of people,
many of whom may not even be aware
that they helped or served as inspiration.
So in no particular order,
and at the risk of leaving out someone:
First and foremost,
&SCons; owes a tremendous debt to Bob Sidebotham,
the original author of the classic Perl-based &Cons; tool
which Bob first released to the world back around 1996.
Bob's work on Cons classic provided the underlying architecture
and model of specifying a build configuration
using a real scripting language.
My real-world experience working on Cons
informed many of the design decisions in SCons,
including the improved parallel build support,
making Builder objects easily definable by users,
and separating the build engine from the wrapping interface.
Greg Wilson was instrumental in getting
&SCons; started as a real project
when he initiated the Software Carpentry design
competition in February 2000.
Without that nudge,
marrying the advantages of the Cons classic
architecture with the readability of Python
might have just stayed no more than a nice idea.
The entire &SCons; team have been
absolutely wonderful to work with,
and &SCons; would be nowhere near as useful a
tool without the energy, enthusiasm
and time people have contributed over the past few years.
The "core team"
of Chad Austin, Anthony Roach, Charles Crain,
Steve Leblanc, Gary Oerbrunner, Greg Spencer and Christoph Wiedemann
have been great about reviewing my (and other) changes
and catching problems before they get in the code base.
Of particular technical note:
Anthony's outstanding and innovative work on the tasking engine
has given &SCons; a vastly superior parallel build model;
Charles has been the master of the crucial Node infrastructure;
Christoph's work on the Configure infrastructure
has added crucial Autoconf-like functionality;
and Greg has provided excellent support
for Microsoft Visual Studio.
Special thanks to David Snopek for contributing
his underlying "Autoscons" code that formed
the basis of Christoph's work with the Configure functionality.
David was extremely generous in making
this code available to &SCons;,
given that he initially released it under the GPL
and &SCons; is released under a less-restrictive MIT-style license.
Thanks to Peter Miller
for his splendid change management system, &Aegis;,
which has provided the &SCons; project
with a robust development methodology from day one,
and which showed me how you could
integrate incremental regression tests into
a practical development cycle
(years before eXtreme Programming arrived on the scene).
And last, thanks to Guido van Rossum
for his elegant scripting language,
which is the basis not only for the &SCons; implementation,
but for the interface itself.
Contact
The best way to contact people involved with SCons,
including the author,
is through the SCons mailing lists.
If you want to ask general questions about how to use &SCons;
send email to &scons-users;.
If you want to contact the &SCons; development community directly,
send email to &scons-devel;.
If you want to receive announcements about &SCons;,
join the low-volume &scons-announce; mailing list.