Free Software by Gregory Guerin
From the description:
Imagine that you could catch signals, raise resource-limits, get mounted file-system info, manipulate file modes, or change effective user ID from Java. Imagine that many of the other interesting and useful POSIX system-calls were also accessible from Java. Imagine that they were organized in an easily understood and usable class library, which could be implemented for different platforms yet still be used transparently by any API-conforming user program.
Stop imagining and start downloading, because that’s what this class library does. It includes a working implementation for Mac OS X, but anyone with moderate JNI and Unix experience can create an implementation for other Unix platforms. It’s even possible to create implementations for non-Unix platforms, such as that operating system whose name starts with ‘Wind’.