edward_plainview

When entering a comment the plugin will load some Javascript values – unique for the visitor – to ensure that the user is a real person.
If Javascript is not enabled in the visitor’s browser, an error message will be shown when submitting the comment.
The spam protection is not enabled for logged-in users.

Plainview Comment Antispam

Prevent comment spam automatically by using Javascript.

tuxlog

LazyCaptcha is a small and lazy plugin to prevent bots from spamming your comments. 
It generates a random image with an easy arithmetic task and checks if the result is correct after the comment is trasmitted. 
It stores the tasks and results in the WordPress database and deletes them after use or two times a day using a wp-cron job. 
It works perfectly on my sites, so I decided to publish it for others on WordPress.org.
<h3>Translations</h3>
LazyCaptcha comes in german and english. Feel free to translate it to other languages and send me the translation so I can include it into the translation repository

LazyCaptcha

LazyCaptcha is a small and lazy plugin to prevent bots from spamming your comments.

Plainview Comment Antispam vs LazyCaptcha