The Zen Grid Framework v3 is a Joomla 3+ only template framework.
The framework is an update to the previous Zen Grid Framework that was used for our Joomla templates prior to January 2013, when we moved to the T3 framework.
The plugin was created to provide a more or less seamless update from older Joomla 2.5 and Joomla 1.5 themes based on the Zen Grid Framework. The framework itself consists of a single plugin and requires the use of a specific Zen Grid Framework v3 compatible Joomla template.