here below is the link to the sources+Windows and Linux binaries (courtesy of the wonderful Jim Ablett) of Stockfish 1.6
http://www.mediafire.com/?ij3oonzkmzh
Diff stat from 1.5.1 is:
33 files changed, 1972 insertions(+), 1742 deletions(-)
So this is the first release where there is a net increment of lines of code, we hope they are worth some ELO points more

Many changes, especially in the search and a lot of small stuff scattered around the sources that now have, at last, reached a good code style quality (at least for our taste).
As usual many thanks to all the people that have contributed privately or here on the forum to bug fixes and patches.
Tord has been out of this release cycle due to his personal activities, but we all hope that in the future he will find time to enjoy again this computer chess passion.
Merry Christmas and Happy New Year
Marco Costalba, Joona Kiiski