WordPress - An open source blogging tool and CMS

WordPress is a free and open source blogging tool and a content management system (CMS) based on PHP and MySQL, which runs on a web hosting service. WordPress is completely customizable and can be used for almost anything. WordPress started as just a blogging system, but has evolved to be used as a full content management system (CMS). One very popular feature of WordPress is its plugin architecture which allows users and developers to extend its abilities beyond the core installation. WordPress has a database of over 26,000 plugins, Each of which offers custom functions and features enabling users to tailor their sites to their specific needs. These customizations range from Search Engine Optimization enhancers to content displaying features, such as the addition of widgets and navigation bars. Changing the Look/ Feel of the WordPress is very easy as there are 1000s of free and paid themes available.

WordPress has 2 variants, WordPress.com (supported by ads) which lets you get started with a new and free WordPress-based blog in seconds, but varies in several ways and is less flexible than the WordPress.org, which you can download and install on your server, but to do this you need to have a webhosting service in the first place and the host should meet the minimum requirements. If your main aim is just to write, then WordPress.com is a great tool for you, but if you're planning for something bigger with more possibilities then you should go for WordPress.org, which gives you full control.

Prior to WordPress 3.0, WordPress supported one blog per installation, although multiple concurrent copies may be run from different directories if configured to use separate database tables. WordPress Multi-User (WordPress MU, or WPMU) was a fork of WordPress created to allow multiple blogs to exist within one installation, but is able to be administered by a centralized maintainer. WordPress MU makes it possible for those with websites to host their own blogging communities, as well as control and moderate all the blogs from a single dashboard. That means on a single installation you can enable your own blogging network or you can use this single installation for your eCommerce website and for your blog also for your business. WordPress MU adds eight new data tables for each blog.