Yawiki is a powerful Wiki system for collaborative document generation. It supports both anonymous and authenticated users. It uses an AreaMap page to generate a hierarchy of pages and navigational elements. It supports page-level access control lists. There is an optional comment system built-in, as well as RSS feeds for individual public pages.
Lame Node System is a Web-based idea repository. It is aimed at people wishing to set up a personal site without the hassles of detailed Web page maintenance. It supports user accounts, flexible HTML theming, and several types of "nodes" (HTML input, files/external links, and pictures).
Rippy the Aggregator is a lightweight RSS aggregator written in vanilla PHP. It downloads headlines from a configurable list of regularly-updated Web sites, and merges the items into a single list of all the latest news. Rippy could be used to keep track of several favourite sites, or as an automatic supply of filler material on a public Web site. It uses local files to store its persistent information, requiring no database and no non-default PHP library support.
The Scout Portal Toolkit (SPT) is a turnkey software package that allows groups or organizations who have collections of knowledge or resources they want to share via the Web to put that collection online without a big investment in technical resources. It includes keyword and fielded search engines, a recommender system, a metadata editor, user agents (push technology to notify users of new resources), forums (bulletin boards), resource quality ratings, resource annotations by users, and support for multiple dynamic user interfaces, selectable on a per-user basis.
Monaural Jerk is a journal or "weblog" system that allows single or multiple authors to easily post content to a Web site. Many standard weblog features have already been implemented including organization of content into (multiple) categories, pagination, calendar-based navigation, "edit this page", "send this to a friend", searching, syndication, and more.
Movable Type is a powerful, multi-user blogging platform. It's widely used as a business blogging tool thanks to the ease with which you can create multiple blog sites. It has a large community and many add-ons available. It's written in Perl and tends to be a bit difficult to install, unless of course you use the JumpBox. This JumpBox provides a basic installation of Movable Type setup with a single blog on the root URL of the system. It's highly recommended that you keep that blog and customize it for your needs rather than starting from scratch. From there, you can add other blogs fairly easily. This JumpBox is based on the 1.1 JumpBox Platform and includes a backup system that supports archiving the state of the JumpBox to NFS, Windows file shares, and Amazon S3.
Pivot is a tool to create weblogs (and to some extent other dynamic Web sites). Pivot is easy to setup, easier to maintain, and even easier to work with. It is template based and fully adaptable to your wishes. Language packs are supported. It is easy to upload and include pictures with your log entries. There is a comment system that remembers your visitors. Automagic archiving can be done by week or month. Stylesheets are used extensively. All data is stored in flat files, so no databases are required.