libmap for Plesk
Of course, it would break the support. But the cases when I needed the support were so rare so it wasn't a big problem.
I installed everything from ports, as it's described in 
http://download1.parallels.com/Plesk/PPP9/plesk-9.2.1-for-pkg-based-os.html
1. Change versions for perl, curl, etc in */Makefile according to your installed versions. Otherwise you will see how perl is deleted and reinstall, deleted and reinstalled... I don't know why but it's written - perl5.8.8 (change to perl5.8.9), so is for curl and - check the others.
2. I restored original /etc/pam.d.
3. libmap.conf. My variants are below. You will need the libraries from libmap.conf (put it in /usr/local/compat/, for example). For amd64 I put there libraries from the i386.
For different versions of Plesk I had to make different libmap.conf, here are my working examples:
Plesk 9.2.1 FreeBSD 7.2, i386, /etc/libmap.conf:
#-------
libpthread.so.2         libthr.so.2
[/usr/local/sbin/sw-cp-serverd]
libc.so.6               compat/libc.so.6
#--------
Plesk 8.3.0, FreeBSD 7.0, amd64, /etc/libmap32.conf:
#--------
libxslt.so.2            lib32/other/libxslt.so.2
libxml2.so.5            lib32/other/libxml2.so.5
libiconv.so.3           lib32/other/libiconv.so.3
libexslt.so.8           lib32/other/libexslt.so.8
libintl.so.8            lib32/other/libintl.so.8
libfreetype.so.9        lib32/other/libfreetype.so.9
libpng.so.5             lib32/other/libpng.so.5
libjpeg.so.9            lib32/other/libjpeg.so.9
libxmlrpc.so.7          lib32/other/libxmlrpc.so.7
libxmlrpc_xmlparse.so.7 lib32/other/libxmlrpc_xmlparse.so.7
libxmlrpc_xmltok.so.7   lib32/other/libxmlrpc_xmltok.so.7
libuuid.so.1            lib32/other/libuuid.so.1
libexpat.so.6           lib32/other/libexpat.so.6
libgpg-error.so.0       lib32/other/libgpg-error.so.0
libboost_filesystem.so  lib32/other/libboost_filesystem.so
libboost_date_time.so   lib32/other/libboost_date_time.so
libgcrypt.so.15         lib32/other/libgcrypt.so.15
libmap.so.3             lib32/other/libpam.so.3
pam_unix.so             lib32/pam_unix.so
#--------
Plesk 9.0.1,  FreeBSD 7.2, amd64, /etc/libmap32.conf:
#--------
pam_unix.so             lib32/pam_unix.so
libc-client4.so.9       ports/libc-client4.so.9
libidn.so.16            ports/libidn.so.16
libintl.so.8            ports/libintl.so.8
libfreetype.so.9        ports/libfreetype.so.9
libpng.so.5             ports/libpng.so.5
libjpeg.so.9            ports/libjpeg.so.9
libboost_filesystem.so  ports/libboost_filesystem.so
libboost_date_time.so   ports/libboost_date_time.so
libcurl.so.4            ports/libcurl.so.4
libxmlrpc_server.so.9   ports/libxmlrpc_server.so.9
libxmlrpc.so.9          ports/libxmlrpc.so.9
libxmlrpc_util.so.9     ports/libxmlrpc_util.so.9
libxmlrpc_xmlparse.so.9 ports/libxmlrpc_xmlparse.so.9
libxmlrpc_xmltok.so.9   ports/libxmlrpc_xmltok.so.9
libuuid.so.1            ports/libuuid.so.1
libexslt.so.8           ports/libexslt.so.8
libxslt.so.2            ports/libxslt.so.2
libxml2.so.5            ports/libxml2.so.5
libiconv.so.3           ports/libiconv.so.3
libgcrypt.so.15         ports/libgcrypt.so.15
libgpg-error.so.0       ports/libgpg-error.so.0
libpcre.so.0            ports/libpcre.so.0
libspf2.so.2            ports/libspf2.so.2
libmysqlclient.so.14    ports/libmysqlclient.so.14
libgnugetopt.so.1       ports/libgnugetopt.so.1
libsqlite3.so.8         ports/libsqlite3.so.8
libboost_program_options.so     ports/libboost_program_options.so.4
libboost_regex.so       ports/libboost_regex.so.4
libdb-4.2.so.2          ports/libdb-4.2.so.2
libexecinfo.so.1        ports/libexecinfo.so.1
libgd.so.4              ports/libgd.so.4
libpopt.so.0            ports/libpopt.so.0
libgssapi.so.8          system/libgssapi.so.8
libkrb5.so.8            system/libkrb5.so.8
libasn1.so.8            system/libasn1.so.8
libroken.so.8           system/libroken.so.8
liblog4cpp_plesk.so.4   plesk/liblog4cpp_plesk.so.4
#--------