nginx 1.0.4Edit
From the official release announcement:
Changes with nginx 1.0.4 01 Jun 2011
*) Change: now regular expressions case sensitivity in the "map"
directive is given by prefixes "~" or "~*".
*) Feature: now shared zones and caches use POSIX semaphores on Linux.
Thanks to Denis F. Latypoff.
*) Bugfix: "stalled" cache updating" alert.
*) Bugfix: nginx could not be built --without-http_auth_basic_module;
the bug had appeared in 1.0.3.