Definition: Joomla 1.5 was a version of Joomla, a free web application platform. It introduced several improvements over previous versions. However, it didn't significantly improve functionality or content management system (CMS) features like drag-and-drop and search engine. The name "Joomla" refers to the original Joomla website developed by Antonios Papageorgiou in 1993, now renamed as Joomla.org, which has evolved into a popular CMS platform for web development.