This plugin will improve SEO by helping search enginess better index your site using sitemaps.
Limit rate of login attempts, including by way of cookies, for each IP. Fully customizable.
Backup and restoration made easy. Complete backups; manual or scheduled (backup to S3, Dropbox, Google Drive, Rackspace, FTP, SFTP, email + others).
Widget Logic lets you control on which pages widgets appear using WP's conditional tags. It also adds a 'widget_content' filter.
Move or copy a WordPress site to another server or to another domain name, move to/from local server hosting, and backup sites.
This plugin blocks distributed botnet brute-force attacks on your Wordpress installation.