QuteCsound
is a frontend for Csound featuring a highlighting editor with
autocomplete, interactive widgets and integrated help. It is a
cross-platform and aims to be a simple yet powerful and complete
development environment for Csound. It can open files created by
MacCsound.

You can get QuteCsound for Windows, OS X and source packages here.
Make sure you get the appropriate package for your platform (.exe
for Windows, and Intel or PPC packages for OS X). You also need to
make sure you get the version of QuteCsound for the version of Csound
you have installed. Csound can be built with floats (32-bit) or
doubles (64-bit) precision, and QuteCsound is built against either
one. If there is no indication (like and 'f' or a 'd' or the words
'float' or 'double'), QuteCsound is built for floats.
QuteCsound
0.4 requires Csound 5.10. Qt from Nokia
is needed to run QuteCsound.
The OS X Packages are available for Intel and PPC systems.
For OS X, you need to get the appropriate version depending on
whether you have Qt installed. If you don't have Qt installed (likely
if you don't know what Qt is), you need the -incQt packages, which
include the necessary parts from Qt. If you have Qt installed, get
the -noQt version which is smaller.
The OS X packages are
compressed files which contain the QuteCsound application bundle.
Just double -click on the package, and you will have the QuteCsound
app, which you can place wherever you like.
The Windows installers will guide you through the installation. The installers contain the Qt libraries as an optional install component.
A source package is provided for other platforms or if you need a special build which is not available. To build QuteCsound, you need Csound, Qt and libsndfile (see below).
Debian and Ubuntu have packages in their official repositories, thanks to Felipe Sateler's work.
To use QuteCsound, Csound must be installed in your machine. It is
not necessary to have Csound while installing QuteCsound, but
QuteCsound wil not run without Csound. You can get Csound here.
The
QuteCsound windows .exe download is an installer. Execute and follow
the directions. The package for OS X is just a compressed file
containing the QuteCsound application.
There is only a basic Quick Reference Guide to QuteCsound for now, but hopefully you'll find QuteCsound very intuitive.
To build QuteCsound you need Qt and its development libraries from
Trolltech,
Csound, and libsndfile
(though you can optionally build without the latter). Naturally you
need a compiler like gcc (for *nix), mingw for Windows or Xcode for
OS X.
QuteCsound uses qmake to build, so you generaly only need to
do:
$ qmake $ make
On OS X, you need to run "qmake", which generates an XCode project, which you can then build within XCode.
You can find help for QuteCsound on the main Csound mailing list, or better yet, join the QuteCsound users mailing list for suggestions, bugs, and general questions or ideas.
QuteCsound was mostly written by Andrés Cabrera, with some help
from users like Felipe Sateler, Daniel Prieto, Andy Fillebrown and
Joachim Heintz. QuteCsound is licensed under the GPLv3. This means
you may use QuteCsound or any portion of it for any purpose, but all
derivates must also be placed under this license.