UnderLinux : In a general focus what
is more secure Gnu/Linux or OpenBSD ? Or other OS ?
Aleph1 : That is a pointless question without
some context. For example, certainly the OpenBSD folks have done an
incredible job creating a secure and stable operating system - an
effort that should be emulated by others - but the application you
are looking to run many not be supported under it. The most secure
OS depends on your requirements.
Even with OpenBSD's success the UNIX security model is very
simplistic. You can certainly write secure applications - see qmail
and postfix for examples - but they require a lot of effort. Linux
is interesting because the are so many groups exploring alternative
security models: privileges, acls, subdomain, SELinux, etc.
NT had potential. It has an interesting security model, but the
legacy code, insecure defaults, complexity, and lack of security
savvy by application programmers used to the Windows and DOS world
have left it with a rather bad track record.
You must also take into account how well the people
administrating the system knows the technology. You can have the
most secure OS but if its misconfigured it will be useless.
Conversely, a good admin is capable to hardening a sloppy OS."