Arasan 11.7 is available from http://www.arasanchess.org.
This is primarily a bug fix release. I don't expect much if any difference in playing strength vs. version 11.6.
Changes in Arasan 11.7 (Feb. 2010):
1) Fix in PGN parser for rare cases where moves need rank + file for
disambiguation.
2) Changes to LMR and other pruning logic.
3) Fix time measurement bug in Linux version.
4) Fix thread deadlock problems on Linux.
5) Convert to POSIX unnamed semaphores for Linux, to ensure semaphore
cleanup on program exit.
6) Multiple other code fixes and warning removals for Linux/Mac compiles.
7) Bug fix in Board::wouldCheck.
8) Increased scores for bishop pair, Rook on 7th
9) Fix UCI mate score output.
10) Fix crash bug in UCI mode on Vista, Windows 7