The goal of the project BioSide is to abstract the execution of workflows in bioinformatics. It aims at offering an easy-to-use client for: - designing complex in-silico protocols, or workflows, - executing these workflows, no matter where the real resources are located. The effort led to a generic workflow execution engine, capable of managing executions on different remote sites. The whole process happens behind the scene, so that the final user is freed from the technical aspects of the execution: the necessary files are transparently moved from one execution platform to another, and the execution engine takes care of all the specificities: initialization, execution (unix processes, soap, Sun Grid Engine, etc.), monitoring of the execution, etc.