The Arduino IDE is great and provides plug-and-play and instant gratification but, sometimes, complex sketches require a more powerful IDE.
I've developed embedXcode, a template for Xcode 4 and Xcode 5 and Xcode 6.
Xcode is the free IDE for Mac OS X and provides many niceties such as: syntax colouring, line numbering, function highlighting, code-sense, template with parameters for a function, check-as-you-type, click-to-error, tool-tip texts, object browser, self documentation, git repository management, code snippets, bookmarks, debugging, ...
embedXcode supports Arduino 1.0 and 1.5 (beta) repositories.
• New! Release 128 of embedXcode supports the Arduino Yún connected to a USB port, and embedXcode+ features upload and console over-the-air, through WiFi or Ethernet.
• New! Release 131 improves reference indexing for code-sense.
And the main benefit is faster development.
embedXcode relies on the IDEs of the boards for an easy installation. The set of makefiles can be used with other IDEs. I use Xcode because I own a MacBook, but I tested the set of makefiles successfully with NetBeans.
As at today, Arduino 1.0 and 1.5 (beta) are supported, as well as 8 other Processing-based Wiring-derived Arduino-like platforms: Adafruit, Arduino, chipKIT and PICadillo, DFRobot, Digispark, Galileo, LaunchPad, LightBlue Bean, Little Robot Friends, Maple, Microduino, RedBearLab, RFduino, Robotis, Spark, Teensy and Wiring.
The embedXcode template also supports the mbed framework for ARM MCU-based mbed-enabled boards.
The dedicated website includes
Check the thread Arduino on Xcode Project — Official Thread on the Arduino forum.