Clarify what versions of Windows are supported, and add Linux
specifically.
diff --git a/Doc/lib/libthread.tex b/Doc/lib/libthread.tex
index 227dd3d..d302958 100644
--- a/Doc/lib/libthread.tex
+++ b/Doc/lib/libthread.tex
@@ -15,7 +15,7 @@
\index{binary semaphores}
\index{semaphores, binary}
-The module is optional. It is supported on Windows NT and '95, SGI
+The module is optional. It is supported on Windows, Linux, SGI
IRIX, Solaris 2.x, as well as on systems that have a \POSIX{} thread
(a.k.a. ``pthread'') implementation.
\index{pthreads}