grosbouff

Pencil Wiki is a simple wiki solution for your WordPress.
Basically, it adds new roles & capabilities that allow your users to add/edit wiki pages (custom post type).
It comes with several widgets and custom templates (that you can override) fully integrated with the Twenty Twelve theme.
Pages are edited backend, but there is a menu on every wiki page with the necessary links; and a wiki index / search input.
Only Administrators and Editors can create new wikis (top-level pages); and Wiki Authors can add pages to it. 
Administrators and Editors can also LOCK some wiki pages (for any reason) or branches; which means they will not be editable anymore by other users.
I voluntarily made the plugin quite simple to avoid making it intrusive (javascript, css, …) and put too many features. I recommend to run it with those plugins : 
* <a href="https://wordpress.org/extend/plugins/member" rel="ugc">Members</a>Members by Justin Tadlock, to manage roles and capabilities 
* <a href="http://mtekk.us/code/breadcrumb-navxt" rel="nofollow ugc">Breadcrumb NavXT</a> by John Havlik, to generate breadcrumbs 
* <a href="https://wordpress.org/extend/plugins/simple-footnotes" rel="ugc">Simple Footnotes</a> by Andrew Nacin, to put footnotes in your wiki pages.
WordPress has a revision system, which is perfect for a wiki. 
Unfortunately, I didn’t find a way to customize it (add revision messages, etc).

Pencil Wiki

Pencil Wiki is a simple wiki solution for your Wordpress.

DannyCooper

Enables a knowledge base post type and section taxonomy.
The plugin adds a Knowledge Base tab to your admin menu, which allows you to add articles just as you would regular posts. This allows you to keep your articles even if you change theme.
The Apollo Theme was built purposely to work with this plugin – <a href="http://crtv.mk/ez5P" title="Apollo WordPress Theme" rel="nofollow ugc">Apollo Theme</a>
<h4>Bugs</h4>
If you find an issue, let us know <a href="https://github.com/DannyCooper/knowledge-base-cpt/issues" rel="nofollow ugc">here</a>!
<h4>Contributions</h4>
Anyone is welcome to contribute to the Knowledge Base CPT plugin.
There are various ways you can contribute:
<ol>
<li>Raise an <a href="https://github.com/DannyCooper/knowledge-base-cpt/issues" rel="nofollow ugc">Issue</a> on GitHub</li>
<li>Send us a Pull Request with your bug fixes and/or new features</li>
<li>Translate the Knowledge Base CPT plugin into <a href="https://www.transifex.com/projects/p/knowledge-base-cpt/" rel="nofollow ugc">different languages</a></li>
<li>Provide feedback and suggestions on <a href="https://github.com/DannyCooper/knowledge-base-cpt/issues?direction=desc&labels=Enhancement&page=1&sort=created&state=open" rel="nofollow ugc">enhancements</a></li>
</ol>

Knowledge Base CPT

Enables a 'knowledge base post' type and 'section' taxonomy.

Pencil Wiki vs Knowledge Base CPT