The Nu git repository now contains all the source code and related build tools to build Nu for Linux and for the iPhone. iPhone support is currently for the simulator only, and so far, I have only tested Linux support on Ubuntu 7.10 running in VMware Fusion.
While there's a lot of interest in the iPhone, the Nu Linux support is what has me the most excited.
Nu on Linux
Since Nu is built on Objective-C and the Foundation library, Nu on Linux requires a cross platform Objective-C compiler (which we have in GCC), an Objective-C runtime (I'm currently using GNU libobjc), and a Foundation library. To get a quick and easy start, I've released NuFound, a repackaging of libFoundation that can be easily built on Linux and that contains a few fixes and changes that make it a more compatible substitute for Apple's Foundation classes. But I'm glad to keep an open mind about other Foundation libraries - if anyone wants to port Nu to a comparably easy-to-build-and-install version of GNUstep or Cocotron, I'll merge in the necessary changes.
While there may be a future for Nu/Linux in desktop applications, to me there are two much more interesting platforms that it now puts within reach:
Cloud computing. Nu and Objective-C can now be used in Linux-based virtual machines that can be run on generic hardware. So we can begin writing and gluing together Objective-C components to build software services on a completely free and open source software stack.
Embedded computing. Systems from large customized application accelerators down to cell phones and camera controllers run Linux using code compiled with GCC. That's now all that it takes to use Objective-C and Nu to build reusable and dynamically bindable components for use on those systems.
As a demonstration, I've released Nunja, a lightweight web server that I built in a day by first writing an Objective-C wrapper for libevent which I then customized with an application layer written in Nu. Nunja builds and runs on both OS X and Linux, and I hope will be a small piece in a rich library of cross-platform Objective-C components.
Nu on the iPhone
When the iPhone SDK was released last week, I couldn't resist the temptation to pause my Linux-related work to see if Nu could be built for the iPhone. Thanks to the iPhone's solid Unix and Objective-C underpinnings, a basic port took less than a day. To build the necessary files to use Nu on the iPhone, use the Nukefile in the iphone directory in the Nu source distribution.
The best way to get involved with any of these projects is to get a github account, fork a repository on github, and put your contributions there. Then I and others can easily pull your changes into our repositories and keep things moving.
If you need a github beta invitation, email me; I have a few left.