A community of practice (Wikipedia) needs a communication platform to collaborate on a subject of their interest. To share experience on practicing and working on knowledge.

Confluence is a team collaboration platform. The projectdoc Toolbox support teams to write documentation in a modular style. Having separate documents for topics makes it even easier to work on a subject collaboratively. Team members edit different documents concurrently and assemble them by using transclusion or reference.

This makes this Wiki platform a perfect fit as a tool set for a community of practice in many cases.

The PDAC1 provides tools to create journals on a personal (Diary from the projectdoc Developer Diaries add-on) and on a team level (using the Iteration doctype of the Doctypes for Agile Planning add-on). The Agile Planning add-on also provides backlogs (Improvement doctype) for a document-based tracking of areas of improvement.

The Core Doctypes allow you to define a library to keep track of external resources, have information about people of the community and relevant external experts in form of a address book, and the Glossary Item doctype to create and maintain a glossary of terms of your domain.

Furthermore the Doctypes for Teamwork provide doctypes to define the rules of your communities communication, specify proven practices in the form of patterns and document a shared repertoire of tools. Using workspaces to spike on new areas and topic spaces to document and maintain relevant information on the subject.

That is not to say that communities need all of the tools sketched out above. This is simply a set of tools to select from and adapt to the community's requirements to work effectively and efficiently together.