DBIx::Password provides an abstraction layer for password maintenance. It is database independent and only overrides the connect method (so it basically behaves as DBI normally does). You provide a single virtual user name in the connect method and the module determines which database/which user/which password to provide.
mod_filter allows you to filter output from other modules inside of Apache. This allows you to implement filters (think Swedish Chef, jive, etc.). You can also use it to retailer output for your locale. This works with HTML documents, mod_perl, PHP, JServ, CGIs, and for that matter just about any sort of custom handler you might have.
mod_layout is an Apache module that provides both a Footer and Header directive to automagically include output from other URIs at the beginning and ending of a Web page. It can be used to wrap documents for a standard look and feel for a site (or to insert banners on any given document in a site). Currently known to support mod_perl, PHP and Apache JServ. Should support just about any type of handler.
Mod Random provides three services. The first service is redirection: you feed it URLs and it will redirect to random URLs that you have loaded. The second is providing environment variables that can be used for implementing ad banner systems. The third is displaying entire pages of random HTML, using its own custom handlers in combination with with random ads and quotes that you feed into the system. It can also supply text via an environment variable called RANDOM_QUOTE, RANDOM_AD, or by environment variables that you specify. This can be used to implement fortune cookies, message of the day, entire random pages, or banner ads.
mod_repository turns Apache into a content storage system with the benefit of storing just one copy of each file submitted to the repository. Upon storing a file a user is given a unique token representing the file. This can be used to create content servers which are abstracted from the filesystem. Files can be placed, retrieved, and deleted from the server.
mod_trigger gives you hooks into each Apache request to launch triggers if certain actions occur. You specify the actions through directives that mod_trigger adds to the Web server. This allows you to, for example, have a script email you when someone is visiting a certain page, let you know when someone from a certain domain is looking through your Web site, etc. This will allow you to fire off scripts/CGI/servlets when these (and a few other dozen) events occur. No modifications are required to the content of your site and users of your server never need to know that a trigger has been put in place.
mod_mp3 turns the Apache Web server into an MP3 or Ogg streaming server. It can play from a list of files, either in order or randomly. It can also be used to cache MP3s into memory and have the server operate entirely from memory. It has an XML-RPC interface for you to write interfaces around and supports retrieving information via XML/RSS.
mod_text2html is an Apache module which is designed to replace Apache's internal text/plain handler. It converts carriage returns into "BR" tags. If it finds valid URLs it turns them into "A HREF" tags, and it does a good job of trying to not muddle up HTML that has been flagged as text. It converts commas and ampersands into HTML entities. It uses the same method as the Unix find utility to determine if a file is text in the first place. If it determines that the file is not text it sends the file, but does so as application/octet-stream.
Web Service Engine for MySQL is a storage engine for the MySQL database. It takes basic SQL and translates this through the engine interface into HTTP request methods. This gives you the ability to create, read, and delete pages on Web servers. Wikipedia becomes a table you can select on from your database.
Mod Methods implements basic GET, HEAD, PUT, UPDATE, OPTIONS, and DELETE methods for Apache. You can write a very simple WebDAV environment using this module (or use it as a backend for the myhttpd engine for MySQL). GET and HEAD in this module just ship files; no execution of CGIs will occur.
The Skeleton Engine is a starting point for creating a MySQL Storage Engine. It comes with everything you need to write a pluggable engine. Autoconf, an initial framework, and scripting tools are all provided. The Skeleton Engine has been the starting point for the PBXT, Nitro, Memcache, AWS, HTTP, and many other engines.
libmemcached is a C client library for interfacing to a memcached server. It has been designed to be light on memory usage, thread safe and to provide full access to server side methods. It also implements several command line tools: memcat, memflush, memrm, memstat, and memslap (for load generation). The library has been designed to allow for different hashing methods on keys, partitioning by keys, and to use consistent hashing for distribution.
Gearmand is the job server component of Gearman. Gearman provides a generic framework to farm out work to other machines, dispatching function calls to machines that are better suited to do work, to do work in parallel, to balance the load of processing, or to call functions between languages.
gearman_execute_by_partition() to simplify map/reduce operations. PHP client fixes. Update to admin interface. gearman_client_run_tasks() will now reset on host failures. Support for namespaces. Lots of documentation updates.