+Inplace editing C<perl -i> of files doesn't work without doing a backup
+of the file being edited C<perl -i.bak> because of windowish restrictions,
+therefore Perl adds the suffix C<.bak> automatically if you use C<perl -i>
+without specifying a backup extension.
+
+Using C<fork()> after loading multiple dlls may fail with an internal cygwin
+error like the following:
+
+ C:\CYGWIN\BIN\PERL.EXE: *** couldn't allocate memory 0x10000(4128768) for 'C:\CYGWIN\LIB\PERL5\5.6.1\CYGWIN-MULTI\AUTO\SOCKET\SOCKET.DLL' alignment, Win32 error 8
+
+ 200 [main] perl 377147 sync_with_child: child -395691(0xB8) died before initialization with status code 0x1
+ 1370 [main] perl 377147 sync_with_child: *** child state child loading dlls
+
+Use the rebase utility to resolve the conflicting dll addresses. The
+rebase package is included in the Cygwin netrelease. Use setup.exe from
+F<http://www.cygwin.com/setup.exe> to install it and run rebaseall.
+
+=back
+
+=head2 Prebuilt methods:
+
+=over 4
+
+=item C<Cwd::cwd>
+
+Returns current working directory.
+
+=item C<Cygwin::pid_to_winpid>
+
+Translates a cygwin pid to the corresponding Windows pid (which may or
+may not be the same).
+
+=item C<Cygwin::winpid_to_pid>
+
+Translates a Windows pid to the corresponding cygwin pid (if any).
+