StopForumSpam - StopForumSpam - a database of known forum and blog spam, its sources and the email addresses reported
hCaptcha - Do you use a captcha to keep out bots? hCaptcha is a drop-in replacement for reCAPTCHA that earns website owners money and helps companies get their data labeled.
Antispam Bee - Say Goodbye to comment spam on your WordPress blog or website.
reCAPTCHA - reCAPTCHA is a free security service that protects your websites from spam and abuse.
Sblam! - Open-source implementation of server-side spam filtering of blog comments and forum posts.
UniqPin - UniqPin is a free for non-commercial use service which destiny improve ability of interfaces detect...