WordPress.org

Improve your WordPress SEO: Write better content and have a fully optimized WordPress site using Yoast SEO plugin.

By: Joost de Valk.

Really Simple CAPTCHA is a CAPTCHA module intended to be called from other plugins. It is originally created for my Contact Form 7 plugin.

By: Takayuki Miyoshi.

Allows you to regenerate your thumbnails after changing the thumbnail sizes.

By: Alex Mills (Viper007Bond).

Adds a more advanced paging navigation interface.

By: Lester Chan and scribu.

Clone posts and pages.

By: Lopo.

Enables the advanced features of TinyMCE, the WordPress WYSIWYG editor.

By: Andrew Ozz.

Connect Google Analytics with WordPress by adding your Google Analytics tracking code. Get the stats that matter.

By: Chris Christoff (chriscct7) and Syed Balkhi.

Akismet checks your comments against the Akismet Web service to see if they look like spam or not.

By: Matt Mullenweg, Ryan Boren, Andy Skelton, Michael Adams (mdawaffe), and others.

Easy Web Performance Optimization (WPO) using caching: browser, page, object, database, minify and content delivery network support.

By: Frederick Townes.

A very fast caching engine for WordPress that produces static html files.

By: Donncha O Caoimh, Automattic, and Brandon Kraft.

This plugin will generate a special XML sitemap which will help search engines to better index your blog.

By: Arne Brachhold.

The Wordfence WordPress security plugin provides free enterprise-class WordPress security, protecting your website from hacks and malware.

By: Wordfence.

Customise WordPress with powerful, professional and intuitive fields

By: elliotcondon.

Just another contact form plugin. Simple but flexible.

By: Takayuki Miyoshi.

Increase your traffic, view your stats, speed up your site, and protect yourself from hackers with Jetpack.

By: Automattic, Adam Heckler, Andrew Duthie, Alex Kirk, allendav, alternatekev, and others.

This is not just a plugin, it symbolizes the hope and enthusiasm of an entire generation summed up in two words sung most famously by Louis Armstrong.

By: Matt Mullenweg.

The most downloaded plugin for WordPress (almost 30 million downloads). Use All in One SEO Pack to automatically optimize your site for Search Engines

By: Michael Torbert, Steve Mortiboy, Dougal Campbell, Peter Baylies, and others.

The most popular WordPress gallery plugin and one of the most popular plugins of all time with over 14 million downloads.

By: photocrati and imagely.

WooCommerce is a powerful, extendable eCommerce plugin that helps you sell anything. Beautifully.

By: Automattic, Mike Jolley, jameskoster, Claudio Sanches, Justin Shreve, and others.

Import posts, pages, comments, custom fields, categories, tags and more from a WordPress export file.

By: WordPress.org.

Build responsive page layouts using the widgets you know and love using this simple drag and drop page builder.

By: Greg Priday and braam-genis.

Allows administrators to globally disable comments on their site. Comments can be disabled according to post type. Multisite friendly.

By: Samir Shah.

Multibyte functionality enhancement for the WordPress Japanese package.

By: Seisuke Kuraishi (tenpura).

Displays Google Analytics reports in your WordPress Dashboard. Inserts the latest Google Analytics tracking code in your pages.

By: Alin Marcu.

The visual editor widget for WordPress.

By: Black Studio, Marco Chiesi, and Francesco Canovi.

Backup and restoration made easy. Complete backups; manual or scheduled (backup to S3, Dropbox, Google Drive, Rackspace, FTP, SFTP, email + others).

By: Backup with UpdraftPlus, David Anderson, and DNutbourne.

Modern two-factor that people love to use: strong authentication without passwords or tokens; single sign on/off; magical login experience.

By: Dave Ross, Jesse Pollak, Andrew Russell, and Laurence.

Take the guesswork out of WordPress security. iThemes Security offers 30+ ways to lock down WordPress in an easy-to-use WordPress security plugin.

By: iThemes, Chris Jean, Aaron D. Campbell, gerroald, and Matt Danner.

Duplicate, clone, backup, move and transfer an entire site from one location to another.

By: corylamleorg and Bob Riley.

Easy to use WordPress Slider plugin. Create responsive slideshows with Nivo Slider, Flex Slider, Coin Slider and Responsive Slides.

By: Matcha Labs.