Evaluation campaigns are the most successful modality for promoting the assessment of the state of the art of a field on a specific task. Within the field of machine translation, the International Workshop on Spoken Language Translation (IWSLT) is a yearly scientific workshop, associated with an open evaluation campaign on spoken language translation. The IWSLT campaign, which is the only one addressing speech translation, started in 2004 and will feature its 13th instalment in 2016. Since its beginning, the campaign attracted around 70 different participating teams from all over the world. In my talk I will present the main characteristics of the tasks offered within IWSLT, as well as the evaluation framework adopted and the data made available to the research community. We also analyse and discuss the progress made by the systems along the years for the most addressed and long-standing tasks and will share ideas about new challenging data and interesting application scenarios to test the utility of spoken language translation systems in real tasks.