Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
New documentation
Internal transitions. Either as part of the transition table or using a state's internal transition table
increased dispatch and copy speed
new row types for the basic front-end
new eUML syntax, better attribute support, macros to ease developer's life. Even VC8 seems to like it better.
New policy for reduced compile-time at the cost of dispatch speed
Support for base events
possibility to choose the initial event