No official changes are available but here is some of them from commit log
on github.
* Add tests for block-form of Buffer::new and MemoryPointer::new
* spec: Test absolute library path.
* DynamicLibrary.c: Avoiding dlsym(dlopen(0,0), sym).
* spec: Replace absolute_.. with expand_path.
* Use rb_thread_call_without_gvl where available.
* Trap & save exceptions from ruby callbacks.
* pkgsrc change: require ruby-rdoc version 3.9.4 or later to build
problem on ruby18 and ruby19.
Exact changes aren't available, please refer:
https://github.com/ffi/ffi/commits/master
== 1.0.0 / 2010-11-30
* Major improvements
* Better handling of non-ruby thread callbacks
* Support for releasing the GIL during C function calls
* Minor improvements
* code cleanups
== DESCRIPTION:
Ruby-FFI is a ruby extension for programmatically loading dynamic
libraries, binding functions within them, and calling those functions
from Ruby code. Moreover, a Ruby-FFI extension works without changes
on Ruby and JRuby.
Discover why should you write your next extension using Ruby-FFI
here[http://wiki.github.com/ffi/ffi/why-use-ffi].
== FEATURES/PROBLEMS:
* It has a very intuitive DSL
* It supports all C native types
* It supports C structs (also nested), enums and global variables
* It supports callbacks
* It has smart methods to handle memory management of pointers and structs
