• Support for taking advantage of rigid bodies in collision detection has been added via the IMP::core::RigidClosePairsFinder.

• All IMP::core::ClosePairsScoreState-related functinality has been optimized and should be noticeably faster.

• The EMBED project has been merged into the IMP::em module. Thus, it is no longer necessary to obtain EMBED separately to build IMP::em.

• All C++ methods which work with std::istream or std::ostream arguments should now be usable from Python: any Python file-like object can be used.

• The SWIG interface now ties in to the reference counting mechanism used in the C++ code, for all classes derived from IMP::RefCounted. So, for example, deleting a Python object should not free the underlying C++ object if another C++ object holds a reference to it, and unrefing a C++ object should not delete it if a Python object still holds a reference to it. There should be no further need to manually keep references to Python objects to prevent things from being prematurely cleaned up. This should be transparent to the user; please report any problems.

• IMP::atom::AtomDecorator no longer inherits from IMP::core::XYZDecorator.