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  Apache HTTP Server Version 1.3
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<H1 ALIGN="CENTER">Overview of new features</H1>

<H2>New Features with Apache 1.0</H2>

<P>New features with this release, as extensions of the Apache
functionality (see also more detailed <CODE>CHANGES</CODE> file) in
the source directory.  Because the core code has changed so
significantly, there are certain liberties that earlier versions of
Apache (and the NCSA daemon) took that Apache 1.0 is pickier about -
please check the <A HREF="misc/compat_notes.html">compatibility notes</A> if
you have any problems.

<UL>

<LI> API for server extensions --- see below for a brief sermon on
philosophy, or see <A HREF="misc/API.html">src/API.html</A> for an actual
overview.  Most server functionality (including includes, CGI, and
most forms of access control) are actually implemented as
API-conformant modules; you can also do other neat stuff (we've
included a sample module, for instance, which one of us is using to
track click-trails using the <A
HREF="http://home.netscape.com/newsref/std/cookie_spec.html">Netscape
cookie mechanism</A>, for visitors who come in through Netscape
clients).  <A HREF="mod/mod_dld.html">Modules</A> can also be loaded
dynamically using GNU DLD.

<P>
The API is not yet quite stable (see src/TODO for some possible
changes), but anything done now will be easily adapted for future
versions --- after all, we have more modules to adapt than you do.

<P>

<LI> <A HREF="process-model.html">New Process Model - much less forking, no
fixed number of children.</A>

We found that many people were using values for "MaxServers" either
too high or too low, and were hanging themselves on it.  The model we
adopted is still based on long-lived minimal-forking processes, but
instead of specifying one number of persistent processes, the
web-master specifies a maximum and minimum number of processes to be
"spare" - every couple of seconds the parent checks the actual number
of spare servers and adjusts accordingly.  This should keep the number
of servers concurrently running relatively low while still ensuring
minimal forking.

<P>

<LI> <A HREF="vhosts/index.html">&lt;VirtualHost&gt; (the configuration
directive for
multiple-homed servers)</A> is more general now.  Just about any srm.conf or
httpd.conf command can go in a &lt;Virtualhost&gt; section, with the
following specific exceptions: ServerType, UserId, GroupId,
StartServers, MaxRequestsPerChild, BindAddress, PidFile, TypesConfig,
ServerRoot.

<P>

<LI> <A HREF="content-negotiation.html">Support for content negotiation of
languages through MultiViews</A>
(*.fr, *.de, *.en suffixes), via the new AddLanguage and LanguagePriority
commands (code written by Florent Guillaume, guillaum@clipper.ens.fr).

<P>

<LI> Significant internal cleanups and rearrangements.  The two externally
   visible consequences of this are that just about all of the unchecked
   fixed limits are gone, and that the server is somewhat pickier about
   config file syntax (noting and complaining about extraneous command
   arguments or other stuff at the end of command lines).

<P>

<LI> XBITHACK is a run-time option, and can be selectively enabled per
   directory --- the -DXBITHACK compile-time option just changes the
   default.  The command which configures it is "XBitHack", which is
   allowed everywhere "Options" is; this takes an argument ---
   "XBitHack Off" turns it off; "XBitHack On" gets you the NCSA
   -DXBITHACK behavior; and "XBitHack Full" gets you the Apache GXBIT
   stuff on top of that.  (-DXBITHACK makes "Full" the default;
   otherwise, it defaults "Off").

<P>

<LI> TransferLog can specify a program which gets the log entries piped to it,
   a la 'TransferLog "| /var/www/my-perl-script -arg valu"' --- this should
   give the same SIGTERM/pause/SIGKILL treatment to the logging process on
   server restarts that a CGI script gets on an aborted request.  NB the
   server is counting on the logging process to work, and will probably hang
   or worse if it dies.

<P>

<LI> <A HREF="mod/mod_log_config.html">Configurable logging module</A> --- this
   is a replacement for the standard plane-jane Common Log Format code, which
   supports a LogFormat directive which allows you to control the formatting of
   entries in the TransferLog, and add some new items if you like (in
   particular, Referer and User-Agent).  EXPERIMENTAL.
</UL>
<P><HR>


<H2>Other features of Apache</H2>
<UL>
<LI><A HREF="mod/mod_dld.html">Dynamically loading modules using GNU DLD</A>
<LI><A HREF="mod/mod_imap.html">Imagemap Module</A>
<LI><A HREF="mod/mod_dir.html#directoryindex">Multiple DirectoryIndex
filenames</A>
<LI><A HREF="mod/mod_asis.html"> &quot;Send as is&quot; file types</A>
<LI><A HREF="mod/mod_include.html#xbithack">XBITHACK last modified</A>
</UL>

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  Apache HTTP Server Version 1.3
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