The Akismet plugin for b2evolution checks feedback through a central service ( http://akismet.com ) against spaminess.
This plugin is no longer necessary for most users because similar functionality has been integrated into b2evolution's core. To add a list of comments to your sidebar, go to Blog Settings > Widgets > Add Widget and click on Comment List.
This plugin adds a widget that displays a list of recent comments in your sidebar.
The YouTube Plugin allows you to search YouTube, select a video from the results and add it to your post. You don't need to have a YouTube account. You don't need to edit the b2evolution HTML Validator. You don't even need to go to YouTube.com. It's all done from inside your b2evolution backoffice.
This plugin allows you to password protect your posts, and visitors would have to enter right password to view post content. All passwords are stored in cookies (if enabled in plugin settings) and visitors don't have to enter them every time. Please note: - it doesn't hide post comments. - it's still under testing, and there might be some bugs.