related-posts-for-wp author-enhancementdefault-post-typefront-endnot-testedready-to-usesuggested-by-clientuser-interaction
leadin extra-wp-core-functionlogin-enhancementnot-testedsocialuser-interactionuser-registrationvery-popular
stop-spammer-registrations-plugin crazynessdeveloper-toolsf5sites-advanced-toolkitin-usemust-haveneed-basic-configurationsecurityuser-registrationvery-popular
really-simple-captcha extra-wp-core-functionf5sites-basic-toolkitready-to-usesecuritysocialuser-interaction