On the homepage you get a big list of WordPress features with code snippets to replace existing plugins. You can filter code snippets by keywords or just browse everything at once. Since everything’s on a single page it’s easy to search through and copy/paste codes as you find them.
The site already has over a dozen different snippets that help you extend WordPress without any plugins. These snippets include custom post types, custom shortcodes, 301 redirects, and adding your own custom JS/CSS files to the header.
Every code snippet has a button to auto-copy the snippet to your clipboard for easy transport. You’ll also find a brief description of each snippet along with links to the WordPress codex for any main functions.
This site is incredible and it’s still a work in progress so there’s room for new contributions.
If you find any code snippets that can replace common WP plugins you should tweet the site’s owner Luke Liasi @lukeliasi. He’s open to all new suggestions and will frequently update to ideally become the ultimate resource to help WordPress users optimize their WP websites.