mod-vhost-ldap is an Apache 2.x module for storing and configuring virtual hosts from LDAP. It supports DocumentRoot, ScriptAlias, ServerName, ServerAlias, ServerAdmin, and SuexecUserGroup directives. It's built on top of mod_ldap, so it uses its caching capabilities and can be used with a threaded Apache httpd.
mod_athena is an Apache-based application load balancer for large systems. It allows the HTTP server to act as a load balancer either internally to Apache's own mod_proxy (for reverse proxying), or externally to machines querying it. Arbitrary statistics are sent to the engine via a simple GET plus query-string interface, from which it will then make decisions based on chosen algorithms.