With 12,000+ known structures, diterpenoids are a prime example of bio-active natural products produced by plants and marine invertebrates. Diterpenoids may be used as highly valuable pharmaceuticals or food ingredients and in many industrial sectors e.g. as anti-fouling agent in the maritime industry. Unfortunately, diterpenoids are typically produced in minute amounts in their host organisms and their structural complexity render them difficult to prepare from fossil resources using organic chemical synthesis. Terpene synthases, cytochrome P450s and acyl transferases are key multienzyme families involved in diterpenoid synthesis. Using state-of-the-art technologies, elucidation of even highly complex biosynthetic pathways is now possible within a reasonably short time frame. Terpenoid metabolism is modular right from assembly of the C5 building blocks to the final structurally complex diterpenoid. Using the approaches of synthetic biology for combinatorial biosynthesis, the functional modules may be assembled in new combinations to expand the landscape of diterpenoid structural diversity into new-to-nature structures. Our elucidation of the entire pathway for forskolin will be presented. Forskolin is a cyclic AMP booster approved for treatment of glaucoma but also used as a weight loss aid. The forskolin pathway is being used as test model system for large scale light driven production of high value diterpenoids following targeting of the pathway to the photosynthetic thylaloid membrane using cyanobacteria or moss as photosynthetic production hosts grown in contained photo-bioreactors. Examples of how to achieve production of interesting anti-fouling compounds will be presented.