Perl-based wiki offers easy customization, extension TWiki, an open source project, is a structured wiki written in Perl. Its active development community has contributed multiple Web applications based on TWiki’s plug-in API, yielding a solution that’s flexible enough for document management, knowledge bases, or wiki message boards.As with similar packages, users browse to pages that are updated using an edit link. TWiki uses wiki text-markup codes rather than WYSIWYG editing, although there are hints on the edit forms to assist newcomers with formatting.TWiki’s functions include automatic links to other Web pages, full text search, e-mail notification when content changes, and the ability to upload (and download) any file as an attachment. Because TWiki focuses on bringing structure to Web sites, pages are automatically grouped into TWiki Webs, which makes it easy to create collaboration groups. Those with coding skills can use variables to build dynamic pages, such as a table of contents or a page of embedded search results. Fine-grained permissions allow administrators to restrict read and write access for departments. TWiki’s straightforward template system allowed me to change the look of my pages, and I employed plug-ins to make my test site more useful, although the latter requires some development skills. For instance, the Headlines utility allowed me to display RSS news feeds, and the Database plug-in allowed me to read from a MySQL database to update information. Other add-on functions include calendaring, graphs, and an action tracker for monitoring the progress of tasks.Although there’s no formal support, TWiki has a decent corporate base, so you should be able to get assistance with just a little research. Although not a turnkey solution, TWiki is more user-friendly than some commercial groupware software. Distributed under the GNU General Public License. TWiki twiki.org Cost: Free Software DevelopmentSmall and Medium Business