Arasan 16.1 is available from http://www.arasanchess.org.
Changes in Arasan 16.1:
1) Fix UCI protocol bug that could cause engine to hang in cases where
ponder is on and game is terminating due to a draw by repetition
or rule.
2) Some speed optimizations for pin detection.
3) Bug fix in razoring code (return razor value from search).
4) Fix time & nps display for UCI (was off by factor of 10)
5) Some pawn scoring changes.
6) Bug fix: correct some of the constants in Attacks class.
7) Fix problem in UCI multi-PV analysis mode.
8) Allow LMR for checking moves and recaptures if they do not
meet the extension conditions (still disable LMR if side
to move is in check).
9) Fix console input handling in Windows.
10) Add -o (output file) option to engine "test" command.
11) GUI uses .chm help file format, for compatibility with Windows Vista, 7, 8.
Mostly bug fixes, but also this version is somewhat stronger than 16.0.
In addition there are some updates/fixes in the opening book.
--Jon