Focused crawls are collections of frequently-updated webcrawl data from narrow (as opposed to broad or wide) web crawls, often focused on a single domain or subdomain.
A drop-in replacement for PHP's default session handler which stores session data in a MySQL database, providing both better performance and better security and protection against session fixation and session hijacking
Hacker101 is a free class for web security. Whether you're a programmer with an interest in bug bounties or a seasoned security professional, Hacker101 has something to teach you.