Alkaline is a full-featured standalone search and index server. The spider is a fully remote indexing daemon which includes support for all standards like robots.txt and "skip" meta tags, and allows multiple distinct configurations and search groups (searching many different sites from your server), including complex regexp indexing paths, authentification, filters for various document formats, XML-based online management and statistics, mrtg-compatible perf numbers, and more.
Aphid (the Apache/Perl HTTP Installation Daemon) provides a quick facility for compiling and installing the Apache Web server with support for SSL via mod_ssl, and with the embedded Perl interpreter provided by mod_perl. It downloads, compiles, and installs the software into the directory of your choice. Aphid places emphasis on providing an intuitive, browser-based interface and keeping a tiny distribution footprint. To date Aphid has been tested on Rehat Linux 6 and 6.2, FreeBSD 4.0, and Solaris 2.6 and 7.
Kannel is a WAP gateway. It attempts to provide this essential part of the WAP infrastructure freely to everyone so the market potential for WAP services, both from wireless operators and specialized service providers, will be realized as efficiently as possible. It also works as an SMS gateway for GSM networks. Almost all GSM phones can use it to send and receive SMS messages, so this is a way to serve many more clients than just those using a WAP phone. Kannel was among the first WAP gateways to be certified as WAP 1.1 compliant.
mod_backhand is a load balancing module for Apache. It provides per-request HTTP redirection within a heterogeneous Apache server cluster. Each request is processed and run through a set of "candidacy functions" to determine which server is best suited to respond. The request is then proxied to that server. Facilities are in place to allow you to write your own dynamically loadable decision making algorithms. Everything about the request and the current availability of resources can be used in the decision-making process.
Lingerd is a daemon designed to take over the job of properly closing network connections from an HTTP server like Apache. This frees Apache from doing the very boring but time-consuming job of "lingering closes", and lets each Apache process go on to the next connection immediately. The end result is that Apache needs fewer processes to handle high loads, which saves memory, reduces kernel contention, and generally makes Apache more scalable.
httplog is a replacement for Apache's 'rotatelogs' and Andrew Ford's 'chronolog'. It allows you to specify a logfile using strftime paramaters in the filename to act as a template. This means that the logs in your logfiles will also be sorted according to the filename. For example, if you specify a logfile of /var/log/http%Y%m%d.log, a new log file would be generated each day, with content for only that one day. It also supports compression of logfiles using gzip, and many other useful functions.