BigApache for Windows
- A free enterprise-ready derivative of Apache.
- http://www.bigapache.org/

Stronghold Enterprise Apache
- Apache redesigned with rigid security features.
- http://www.redhat.com/software/stronghold/

WebTen
- Apache-based web server for MacOS Classic (9.x and below).
- http://www.tenon.com/products/webten/

Oracle HTTP Server Powered by Apache
- Apache adapted to work with Oracle's Internet Application Server.
- http://www.oracle.com/ip/deploy/ias/index.html?web.html

IBM HTTP Server
- Features support for SSL V2 and V3, Fast Response Cache Accelerator (Windows NT only) and native platform install.
- http://www-4.ibm.com/software/webservers/httpservers/

StWeb Stratos Web Application Server
- Apache rewritten to serve pages written in the Stratos programming language.
- http://www.stweb.org/

Apache-SSL
- Apache with Secure Sockets Layer (SSL) built-in, not as a module.
- http://www.apache-ssl.org/