Add Bill Janssen's notes on configuring threads.
diff --git a/README b/README
index 5a9db6f..6975d6c 100644
--- a/README
+++ b/README
@@ -304,6 +304,62 @@
in the resulting binaries of PYTHON15.DLL and PYTHON.EXE.
+Configuring threads
+-------------------
+
+The main switch to configure threads is to run the configure script
+(see below) with the --with-thread switch (on DEC, use
+--with-dec-threads). Unfortunately, on some platforms, additional
+compiler and/or linker options are required. Below is a table of
+those options, collected by Bill Janssen. I would love to automate
+this process more, but the information below is not enough to write a
+patch for the configure.in file, so manual intervention is required.
+If you patch the configure.in file and are confident that the patch
+works, please send me the patch. (Don't bother patching the configure
+script itself -- it is regenerated each the configure.in file
+changes.)
+
+Compiler switches for threads
+.............................
+
+ OS/Compiler/threads Switches for use with threads
+ (POSIX is draft 10, DCE is draft 4) (1) compile only (2) compile & link
+
+ SunOS 5.{1-5}/{gcc,SunPro cc}/solaris (1) -D_REENTRANT (2) -mt
+ SunOS 5.5/{gcc,SunPro cc}/POSIX (1) -D_REENTRANT
+ DEC OSF/1 3.x/cc/DCE (1) -D_REENTRANT (2) -threads
+ (butenhof@zko.dec.com)
+ Digital UNIX 4.x/cc/DCE (1) -D_REENTRANT (2) -threads
+ (butenhof@zko.dec.com)
+ Digital UNIX 4.x/cc/POSIX (1) -D_REENTRANT (2) -pthread
+ (butenhof@zko.dec.com)
+ AIX 4.1.4/cc_r/d7 (nothing)
+ (buhrt@iquest.net)
+ AIX 4.1.4/cc_r4/DCE (nothing)
+ (buhrt@iquest.net)
+ IRIX 6.2/cc/POSIX (nothing)
+ (robertl@cwi.nl)
+
+
+Linker (ld) libraries and flags for threads
+...........................................
+
+ OS/threads Libraries/switches for use with threads
+
+ SunOS 5.{1-5}/solaris -lthread
+ SunOS 5.5/POSIX -lpthread
+ DEC OSF/1 3.x/DCE -lpthreads -lmach -lc_r -lc
+ (butenhof@zko.dec.com)
+ Digital UNIX 4.x/DCE -lpthreads -lpthread -lmach -lexc -lc
+ (butenhof@zko.dec.com)
+ Digital UNIX 4.x/POSIX -lpthread -lmach -lexc -lc
+ (butenhof@zko.dec.com)
+ AIX 4.1.4/{draft7,DCE} (nothing)
+ (buhrt@iquest.net)
+ IRIX 6.2/POSIX -lpthread
+ (jph@emilia.engr.sgi.com)
+
+
Configuring additional built-in modules
---------------------------------------