rustybroomhandle

Allows a Buddypress group administrator to customise their group with CSS via the “Group Custom CSS” tab under the group’s Admin page. Also supports preset themes.
NOTE: Even though this plugin can just be dropped in and used on your site, the css in the code is only really garaunteed to work with the default Buddypress theme, and it is assumed that you as a site builder will customise it to fit your site’s needs.

Buddypress Group CSS

Allows a Buddypress group administrator to customise their group with CSS via the "Group Custom CSS" tab under the group's Admin page.

Christian Wach

Commentpress

CommentPress Core is an open source theme and plugin for WordPress that allows readers to comment in the margins of a text. Readers may comment paragraph-by-paragraph, line-by-line, block-by-block or by selecting text (coming soon to touch devices).
Annotate, gloss, workshop, debate: with CommentPress Core you can do all of these things on a finer-grained level, turning a document into a conversation. It can be applied to a fixed document (paper/essay/book etc.) or to a running blog. Use it in combination with BuddyPress and Groupblogs to create communities around your documents.
Please note: for the time-being, this plugin works best when the Gutenberg editor is disabled. If you want the simplest CommentPress experience in WordPress 5.x please install the Classic Editor or Gutenberg Ramp plugin to manage the post types on which the Gutenberg editor is enabled.
Please note: this plugin comes bundled with three official themes, one of which must be active for CommentPress Core to function. The “CommentPress Modern Theme” will be auto-activated when the plugin is first activated. The old “CommentPress Default Theme” is still included for those who wish to stay with it or have built their own child themes for it. Since version 3.9 a new “CommentPress Flat Theme” is included for those who want an alternative layout. If you are upgrading from a previous version of CommentPress (3.0.x – 3.3.x), please follow the instructions in the Installation section before doing so.
For further information and instructions please see the <a href="http://www.futureofthebook.org/commentpress/" rel="nofollow ugc">CommentPress website</a> or visit the plugin’s <a href="https://github.com/IFBook/commentpress-core" rel="nofollow ugc">GitHub repository</a>. Contact the developers by email at <a href="mailto:cpdev@futureofthebook.org" rel="nofollow ugc">cpdev@futureofthebook.org</a>.
For sites hosted in the European Union, please note: the “CommentPress Default Theme” makes use of cookies, but for presentational purposes only. If you intend to use the “CommentPress Default Theme” on a public site, you may need to inform visitors of this.
Many thanks to the following for translations:
<ul>
<li>French – <a href="https://wordpress.org/support/profile/pouhiou">Pouhiou</a></li>
<li>Spanish – Andrew Kurtis from <a href="http://www.webhostinghub.com/" rel="nofollow ugc">WebHostingHub</a></li>
<li>Dutch – Gerrit Jan Dijkgraaf</li>
<li>German – Chris Witte</li>
</ul>

CommentPress Core

CommentPress Core allows fine-grained commenting in the margins of a text. Use it to annotate, workshop or debate a social text in a social context.

Buddypress Group CSS vs CommentPress Core