Arduino Uno

The Arduino Uno board is an affordable micro-controller (reference) designed and built in Italy around a 8-bits ATmega328 (reference). 

The approach may sound minimalistic but it provides the perfect way to test and learn.
The IDE or integrated development environment offers a C++-based dialect. It comes in two flavours: 
  • Arduino 23 close to the Wiring framework, 
  • and Arduino 1.0 on its own. 
Both are mainly compatible but there are many exceptions.

As Processing-based Wiring-derived, it is platform-agnostic and runs on either Windows, Mac OS X or Linux.

Looking for more features, I designed a template I could use with Xcode:  embedXcode.
The simple board can be extended with shields. There are shields for any usage. Building one's own shield is even possible!

Pros

  • The reference!
  • Many shields and libraries available
  • True plug-and-play 

Cons

  • Still a 8-bit micro-controller
  • New framework 1.0 no longer compatible with the Wiring framework 

Wrap-Up

  • Perfect to start with embedded computing
  • The reference needs a refresh urgently due to intensive competition from 16- and 32-bit boards

Links

Website 
Hardware
Software
Forum