The MapReduce programming model offers a simple and efficient way of performing distributed computation over large data sets. To enable the usage of MapReduce in the cloud, Amazon Web Services offers Elastic MapReduce (EMR), a web service enabling users to easily run MapReduce jobs by leveraging Amazon resources (i.e. compute and storage). EMR takes care of tasks such as resource provisioning, performance tuning, and fault tolerance thus allowing the users to concentrate on the problem to be solved. However, EMR is restricted to Amazon's resources and is provided at an additional cost. In this paper, we present the design, implementation, and evaluation of Resilin, a novel EMR API-compatible system to perform distributed MapReduce computations. Resilin goes one step beyond Amazon's proprietary EMR solution and allows users (e.g. companies, scientists) to leverage resources from one or multiple public and/or private clouds. This gives Resilin users the opportunity to perform MapReduce computations over a large number of potentially geographically distributed resources. An extensive experimental evaluation conducted on multiple clusters of the Grid'5000 experimentation testbed shows that Resilin enables the use of geographically distributed resources with only limited impact on MapReduce jobs execution time.