Overview: IBM HTTP Server
IBM HTTP Server product features IBM HTTP Server documentation

Overview of the Product

IBM HTTP Server powered by Apache is a Web server based on the Apache Web server developed by the Apache Group (www.apache.org). IBM HTTP Server includes some functions not available in the Apache Web server developed by the Apache Group. IBM HTTP Server offers:

  • Support for SSL secure connections.
  • Fast Response Cache Accelerator (Windows NT and AIX only) -
    IBM has extended Apache to work with IBM Fast Response Cache Accelerator (Cache Accelerator). The Cache Accelerator is an in-kernel mini HTTP GET engine and HTTP content cache that enables serving static web pages significantly faster than Apache web server without the Cache Accelerator. By default, the Cache Accelerator is enabled. The Cache Accelerator can be completely disabled through configuration file directives.
  • WebDAV to collaboratively edit and manage files on remote Web servers.
  • Ability to produce dynamic content with FastCGI.
Applies to AIX operating system Applies to Windows operating system The addition of these features required minor modifications to several of the base Apache source code files:
  • New IBM-specific modules for:
    • Secure Sockets Layer (SSL)
    • Fast Response Cache Accelerator (Windows NT and AIX only)
  • Installation of afpa.sys device driver in system32/drivers system directory (Windows NT only)

It is not possible to rebuild the entire IBM binary distribution with the given source due to legal restrictions on the SSL technology. However, the Apache source is included, from which IBM HTTP Server is based. You can write an Apache module that runs with IBM HTTP Server.

The Apache Web server was originally designed and developed for UNIX systems. Apache V1.3.0 was the first major release of Apache that included support for MS Windows. The Windows port of Apache includes many of the most frequently requested new features, including an API to enable extending the web server function, and a module that supports a subset of Microsoft ISAPI (in other words, Microsoft's Web server API).

The most notable difference between the UNIX version of Apache and the Windows version of Apache is that Apache for Windows is a threaded Web server (requests are processed per thread) rather than a process based web server (requests are processed per process). There are potential performance gains that are possible on a threaded web server that have not yet been realized by Apache for Windows.

Applies to Windows operating system

Note: IBM HTTP Server powered by Apache for Windows NT will not run on Windows 95 or Windows 98. If you need an Apache Web server for Windows 95 or Windows 98, you can get the source (and possibly the binary install images) from www.apache.org.

New Functions in This Release

New functionality for this release includes:

  • Keyfile, SSLV2Timeout and SSLV3Timeout directives are now virtual host and global-based. See SSL Directives for more information.
  • Hardware Cryptographic Support: Rainbow Cryptoswift PCI with BSAFE support, Ncipher NForce Accelerator (accelerator mode and key stored accelerator mode) and IBM 4758 Model 023 with PKCS11 support. See Enabling Cryptographic Devices for SSL for more information.
  • Certificate Revocation List (CRL) enablement. See Enabling Certificate Revocation List (CRL) in SSL for more information.
  • Transaction Layer Security (TLS) enablement. See CipherSpec for more information.
  • Additional TLS and SSLV3 Cipher Specs:
    See CipherSpec for more information.


The documentation available as of the date of this release is included in HTML format in the ./share/htdocs/manual/ibm directory. For the most up-to-date documentation, visit the IBM HTTP Server Web site.

Other Sources of Information

There are a couple of very good Internet news groups covering HTTP servers in general. They have information about all the popular Web servers. These news groups might help you find answers to your questions, so check the news group archives first:

  • USENET news.software.ibm.com, ibm.websphere.http-servers
  • http://www.dejanews.com/
  • bg.xp?level=comp.infosystems.www.servers
  • USENET newsgroup comp.infosystems.www.server.ms-windows
  • USENET newsgroup comp.infosystems.www.servers.unix


See the file called LICENSE.IBM


We wish to acknowledge the following copyrighted works that make up portions of IBM HTTP Server based on Apache software:

Portions of this software were developed at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign.

This software contains code derived from the RSA Data Security Inc. MD5 Message-Digest Algorithm, including various modifications by Spyglass Inc., Carnegie Mellon University, and Bell Communications Research, Inc. (Bellcore).

This package contains software written and copyrighted by Henry Spencer. See the file called src/regex/COPYRIGHT.

The NT port was started with code provided to IBM HTTP Server based on Apache Group by Ambarish Malpani of ValiCert, Inc. (www.valicert.com).

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