To support loading dynamic libraries on Syllable and Linux, the generator for the Red/System ELF backend needed to be extended. The Syllable project has already contributed two library bindings to the Red project: an almost complete binding with the standard C library at the ANSI C level, and a high performance binding for the ZeroMQ messaging system. These libraries can now be used from Red/System programs, providing good coverage for basic programming needs and advanced communication programming. A network server and its messaging client are quite easy.
The Red/System compiler is currently written in REBOL 2, until it will be rewritten in Red. Initially, it required the graphical REBOL/View version of REBOL, but it has been freed from that dependency, so REBOL/Core is now sufficient. The result is that the compiler can now run on Syllable Server and on Solaris Sparc. Generic x86 Linux, FreeBSD, OpenBSD, Mac (Intel and PowerPC) and Windows were already supported. Red/System programs can currently be compiled for Syllable Desktop, Linux (and thus Syllable Server) and Windows. Experimental programs have already been compiled for x86 FreeBSD and for a new code generator for ARM processors. A backend for OS X's Mach-O executable format is also in the works. Installation instructions are here.
Cross-compiling is trivially easy with Red. For example, the canonical demo program can be compiled for Syllable Desktop on Syllable Server or any of the other supported platforms like this:
rebol -s rsc.r -t Syllable %/path/to/tests/hello.reds
You can cross-compile a Windows program from Syllable Server or any of the other supported platforms like this:
rebol -s rsc.r -t MSDOS %/path/to/tests/hello.reds