Overview
Compilers needed not include the TR1 components to be conforming to the C++ standard, because TR1 proposals were not part of the standard itself, but only a possible additions that were still to be ratified. However, most of it was available from Boost, and several compiler/library distributors implemented all or part of the components. TR1 was not a complete list of additions to the library that were going to appear in the next standard, C++11. For example, C++11 includes thread support library that is not available in TR1.
The new components were defined in the std::tr1 namespace to distinguish them from the then current standard library.
There is also a second technical report, C++ Technical Report 2, planned for publishing after C++11 .
Read more about this topic: C++ Technical Report 1