Open Source Software for Wordpress
Rooftop
Rooftop is a open source and managed, API-only implementation of the WordPress CMS. With Rooftop, developers can harness the power of WordPress and write frontends in any language. Rooftop can be used to build websites, web applications and mobile applications.
Contact Form Builder for WordPress
Contact Form Builder is a popular plugin used to create forms for WordPress-powered sites. With Contact Form Builder for WordPress it's simple to create feature rich forms that can capture contact information and other useful form data.
Contact Form 7
Contact Form 7 is a WordPress plugin that can be used to create and manage multiple contact forms. The plugin allow you to customize your forms and connect them to email to send confirmation emails designed with flexible and simple markup. Contact Form 7 also provides CAPTCHA and spam filtering with Akismet.
bbPress
bbPress is forum software from the creators of WordPress. With bbPress you can quickly setup a forum for asyncronous discussion and subscriptions for your WordPress-powered site.
W3 Total Cache
W3 Total Cache (W3TC) is a WordPress plugin that improves the SEO and user experience of your site by increasing website performance and reducing load times. With W3 Total Cache, it's simple toimplement caching strategies and a content delivery network (CDN) for your WordPress-powered website or blog.
MainWP
The MainWP WordPress plugin is a free and open-source, self-hosted solution for managing multiple WordPress sites from a single dashboard. With MainWP you can manage posts and pages, controlling users, making backups and performing updates through the unified MainWP dashboard. All of which will minimize the time and cost of maintaining multiple WordPress sites.
Openverse
Openverse is a platform for Creative Commons licensed digital works created by Automatic, the company behind WordPress. With Openverse you can browse through and download over 600 million artworks for reuse. Openverse is available as a web application and can also be accessed with a dedicated WordPress plugin.
Jetpack
Jetpack is the WordPress toolkit developed by Automatic, the developers of WordPress. The plugin provides security, performance, marketing and design tools for WordPress powered websites. Jetpack allows over 5 million WordPress users to monitor site changes, debug, troubleshoot and maintain a healthy and secure website.
All-in-One Video Gallery
All-in-One Video Gallery is a free video gallery for WordPress. With All-in-One Video Gallery users can add videos as posts on their WordPress-powered website. The plugin handles everything needed to build a scalable, searchable, SEO optimized video gallery or video sharing site.