datagutten

The project is inspired by RDP Wiki-Press Embed by Robert D Payne. Some code is also copied (noted in source).
The difference is that this is simpler. It contains as little CSS as possible to be able to customize it for each theme.
Links are rewritten to make the users able to navigate in the wiki without leaving your wordpress page.
The text on the wiki image page will be added as a title=”” tag to the image in wordpress, so by using the plugin <a href="http://archetyped.com/tools/simple-lightbox" rel="nofollow ugc">simple-lightbox</a>, the text will be shown below the image in the lightbox.
It is developed for use with a private MediaWiki install, but it might work with wikipedia as well.
<h3>Tested themes</h3>
Virtue: Works well 
WP-Forge: Works well 
Twenty Ten: Trouble with image alignment 
Twenty Thirteen: Works well 
Twenty Fourtenn: Trouble with image alignment, pages get very narrow 
Twenty Fifteen: Trouble with image alignment

Wikiembedder

Embed MediaWiki in a wordpress site and allow users to navigate the wiki without leaving your wordpress page.

Nico Danneberg

Adds explaining tooltips querying their content from a <a href="https://www.mediawiki.org" title="see MediaWiki docs" rel="nofollow ugc">MediaWiki</a> installation, e.g. <a href="https://www.wikipedia.org" title="see the well-known Wikipedia" rel="nofollow ugc">Wikipedia.org</a>. Therefore shortcodes can be used in Posts and Pages to mark keywords and link them to public Wiki pages. The well-known package of <a href="https://calebjacob.github.io/tooltipster/" title="Tooltipster rocks :)" rel="nofollow ugc">Tooltipster</a> is used to create the nice and themable tooltips.
Main features of the current version are:
<ul>
<li>Setup at least one wanted Wiki base and several other options at a backend page</li>
<li>Integrate the Wiki tooltip in Posts and Pages using a handy popup in Gutenberg editor or simple shortcodes</li>
<li>Shortcodes can be created by a <a href="https://codex.wordpress.org/TinyMCE" rel="nofollow ugc">TinyMCE</a> plugin, too</li>
</ul>

WP Wiki Tooltip

Adds explaining tooltips querying their content from a MediaWiki installation, e.g. Wikipedia.org.

Wikiembedder vs WP Wiki Tooltip