This is OpenCV 2.1
The major changes since v2.0:
* tons of bug fixes, much better test coverage.
* TBB instead of OpenMP; dynamic SSE detection.
* SWIG-based Python bindings are no longer supported.
Python samples rewritten using the new interface.
* more complete support for 64-bit Win and Mac OSes, including highgui.
* better stereo correspondence algorithm (SGBM), see opencv/samples/c/stereo_match.cpp
* grabcut image segmentation algorithm. see opencv/samples/c/grabcut.cpp
... and more.
The detailed changelog is available at https://code.ros.org/svn/opencv/trunk/opencv/doc/ChangeLog.htm
For the list of prerequisities and more detailed installation guide,
please, see http://opencv.willowgarage.com/wiki/InstallGuide
Here is the procedure at glance:
1. tar -xjf OpenCV-2.1.0.tar.bz2
2. mkdir opencv.build
3. cd opencv.build
4. cmake [<extra_options>] ../OpenCV-2.1.0 # CMake-way
5. make -j 2
6. sudo make install
7. sudo ldconfig # linux only
* On MacOSX 10.5 and earlier Cocoa and QTKit bindings do not compile and/or do not work, so it is recommended to pass WITH_CARBON=ON and WITH_QUICKTIME=ON to CMake.