Arduino's extraordinary popularity has made it the focus of innovation for hardware and sofware hackers everywhere. The result is that they're wringing a suprising amount of performance out of a 16 MIPS chip:. Here are two recent advances:
--"Easy multithreading on Arduino with Concurrency
Enjoy programming microcontrollers, but frustrated about how difficult it can be to get them to do more than one thing at a time? Well, then you might be interested in Concurrency, an open source programming language and environment specifically designed with multithreading in mind. That means you can write programs that do multiple things at the same time, without interfering with each other. Of course, you could achieve the same things using a stock Arduino with some crafty coding or timer interrupts, however using a purpose-built language such as this could be a great way to get your feet wet in threaded computing. Check out their website for source code and Creative Commons-licensed tutorials!"
--An Arduino Operating System
"Pyxis OS is an operating system developed for the Arduino. It has been designed to allow Arduino users a greater level of freedom and capability than they currently have. Chief among Pyxis' list of features is its built-in ability to run compiled programs directly from a microSD card. Pyxis can switch between these programs and run as many as you can fit on your card.
The Pyxis programming language not only allows you to take advantage of many of the commands you're used to when developing for a standard Arduino (such as pinMode, digitalRead/Write, analogRead/Write, delay and more) but also expands on them with built-in LCD functions (such as drawLine, fillEllipse, etc).
In addition to using the Pyxis programming language you can access, modify and control the Pyxis OS directly from the Arduino environment. Libraries give you access to powerful abilities that are simply not available without Pyxis. For example, create a Textbox, Button, Progressbar, Combobox, or Checkbox in a single line of code and let Pyxis do all the work of tracking the object and updating the screen for you!"