The Amazon Forest Inventory Network is a long-term, international collaboration to understand the dynamics of Amazon ecosystems. Since the turn of the millennium we have jointly developed a framework for systematic monitoring of the forests from the ground-up. This is centred on permanent forest plots that track the behaviour of individual trees and species, and includes extensive collection of soil and plant biogeochemical data, as well as more intensive, high frequency monitoring of carbon cycle processes at key sites. RAINFOR works with partners across the nations of Amazonia, taking account of the modulating role of environmental variables like soil nutrition, and the need to help develop new generations of Amazon ecologists. The work of RAINFOR is currently supported by funding agencies in Brazil, Colombia, the UK, and the EU.