reegle is an internet search engine specifically covering the fields of renewable energy and energy efficiency. It was originally developed in 2005 by REEEP and REN21 as a public resource, with funding from the governments of:
- United Kingdom (Department for Environment, Food and Rural Affairs)
- Germany (Federal Ministry for Environment, Nature Conservation and Nuclear Safety)
- Netherlands (Ministry of Housing, Spatial Planning and the Environment).
The site was substantially revised in April 2009 to be more user-friendly.