Twin directories of X.500:

[DIR]  ftp://ftp.funet.fi/.m/mirrors2/papa.indstate.edu/winsock/X.500/
[DIR]  ftp://ftp.demon.nl/disk2/winsock-l/X.500/
[DIR]  ftp://ftp.uni-heidelberg.de/pub/net/winsock/winsock-l/X.500/
[DIR]  ftp://ftp.dfn.de/pub/osi/X.500/
[DIR]  ftp://ftp.su.se/pub/security/pca/docs/X509/ITUnov96/X.500/
[DIR]  ftp://ftp.ps.pl/dsk0/papa.indstate.edu/winsock-l/X.500/
[DIR]  ftp://ftp.wu-wien.ac.at/pub/info/nettools/gnrt-by-chapters/X.500/