With „ Progress in Biogas - Biogas production from agricultural biomass and organic residues“ an international congress took place in 2007, with 400 participants from more than 40 nations whose great appeal started and the activities followed then.The international congress aims at showing the development, state of technology and economy of the biogas production worldwide. Practitioners, engineers, scientists and politicians will present and discuss the developments in the fields of process engineering, political/ social frameworks and utilisation of the fermentation products. Exemplary practical experiences confirm the positive developments in this fast developing field of technology and show the business possibilities.For the plenary session and the workshops we are seeking papers dealing with the following topics:   1. Biogas production and Biogas potential from agricultural biomass and organic residues (Africa, Asia, USA, South-America and Europe)   2. Political framework for the implementation and development of biogas production, reduction of barriers (country specific solutions)   3. Progress in production technologies (plant size, process engineering of digestor, automation of the digestion process)   4. Progress in substrate supply and treatment (animal excrements, agricultural byproducts, organic residues, energy crops)   5. Progress in measuring and biological process control   6. Progress in gas utilisation techniques (improvement in efficiency, prevention of emission)   7. Optimal use of digestate (treatment of digestate, improvement of the manure, reuse of nutrients)   8. Conflicts and barriers (sustainability, environmental and social aspects)   9. Show cases for cooperation in the production and use of biogas