There are many open source solutions out there available to develop your social network. Why reinvent the wheel and start from scratch? I will list open source solutions based on PHP and MySQL that can be used for a social network.

* Joomla - It is a very popular open source for web development because it is very versatile with many available modules to increase the overall functionality. In addition, it has a track record being the best to work with for web designers because of the rich and colorful templates, customization option, extensions and components available. Web development is easier for those developing a large scale community site.

* Drupal - It has many advantages concerning web development. From a marketing and development point of view, Drupal is more favored because it provides SEO friendly URL re-write module. In addition, the same login detail can be used for different sites in Drupal. Granting access permission on Drupal is very well structured when giving user permissions via admin panel. The user management approach of Drupal is a good CMS for an online community development. Drupal has extensions as well like Joomla, but not as numerous.

* Elgg - It is an open source software used for social networking. It supports features for blogging, networking, groups, profiles, and file sharing. It has a lot of plug ins that allows users on different social networks to collaborate like all open source. This is a growing open source for social network development. The community that use Elgg is growing rapidly.

* PHPizabi - PHPizabi is developed with focus on security. There are three administrative security layers and internal structure management. The application seems to be fast loading and has a reputation of supporting large communities. Modules are supported on their site in which web developers can expand functionality and features. It is easy to program. The abundance of programmers is not as many compared to Joomla and Drupal. Some of the most noticeable features are customizable profiles, internal message system, online/offline status, friend invitations, photo gallery, smilies, comments and all the cool stuff used around.

* Dolphin - It is not as feature rich as listed above. However, it has many basic social networking elements found in popular social network sites such as MySpace. Like any social network, the mian part is the profile, and the Dolphin platform has customizable profile fields, a profile rating system, profile comments, profile photos, and a photo gallery and blog. Dolphin’s profile system contains a several customizable elements. Users can change their background picture and color and that’s about it. Also, Dolphin does not contain any user defined privacy settings determining who can view one’s profile, blog, and photos.

Those are some of the popular social networking platforms out there. They are all actively being improved by the code author as well as the community. Having these web developmental options makes it easier in attaining your envisioned social network. The core components of all the platforms mentioned above make developmental easier because it is available already. Above all, there is no point in reinventing the wheel now and develop a social network from scratch.