Micro-organisms are found in virtually all environments. Typically, they form the base of the food chain (such as plankton in the sea) and play essential roles in their ecosystems. There is often a complex interplay between different micro-organisms, with some organisms requiring that others be present in order for them to exist. When there is an imbalance within a community, this can lead to severe effects, such as disease in the human gut, or the inability for plants to grow efficiently in soil. An understanding of the composition and interplay within the communities allows us to potentially manipulate them. Thus, there is intense research into micro-organism communities in many different fields, such as improving livestock yields, the recovery from bacterial infections using fecal transplants and the efficient production of biofuels. Many of these communities also contain important proteins that could be useful to the biotechnological and pharmaceutical industries, such as enzymes involved in the production of antibiotics. Metagenomics is the study of these different micro-organism communities, which is achieved by isolating the DNA from the organisms within an environmental sample (e.g. water, soil, animal stool), sequencing the DNA, followed by the computational analysis to decode which organisms are present and the functions they might be performing. This computation is complicated: (1) there is a huge amount of data; (2) The sequence data is a jumbled mix of fragments from different organisms; (3) Decoding the DNA is hard - typically >90% of organisms within a sample are not well characterised. This proposal brings together three major resources within the field of metagenomics data archiving and analysis. The European Nucleotide Archive (ENA) is a repository of DNA sequence data. Importantly, ENA also captures metagenomic contextual data, such as where and when the sample was taken, how the DNA was extracted and sequenced. The EBI metagenomics portal (EMG, UK) and MG-RAST (MGR, US) are two metagenomics sequence analysis platforms. Uniquely, they represent the only free to use services, whereby researchers can upload sequence data and have it analysed without restriction. Despite the widespread use of metagenomics, currently the community lacks standards to ensure that metagenomics sequence data and the derived functional and taxonomic information are deposited within a database of record. Consequently, the navigation between metagenomics datasets is very difficult for even experienced users. As they offer slightly different, yet complementary, analysis services, there is often the desire to have a metagenomics dataset analysed by both resources. But, the number of equivalent datasets between the two resources is unknown. Unless a user has prior knowledge about equivalent projects, they remain disconnected. Also, sequence data submitted to MGR may not necessarily be deposited in ENA. We propose to set up a computational framework, termed Metagenomics Exchange (ME), to enable metagenomics datasets and the results of their analysis to be linked. All sequences will become available to the research community via ENA and analysis results we be automatically exchanged between EMG and EMR. The ME will be implemented to enable other metagenomics analysis providers to join, and so that it can be used by researchers wishing to perform large scale analyses. We will also investigate ways that our own pipelines can be enhanced through the use of the ME, sharing software and processing tasks, for example. This will lead to computational savings, increasing the capacity for metagenomics analysis. We will also generate a knowledge transfer forum, enabling the exchange of ideas on a range of topics, from hardware solutions to algorithms. Finally, we will undertake a research program to investigate the optimal combination of pipeline analysis components, and whether a single, unified analysis pipeline could be engineered.