Social software enhances or intermediates communications through the Internet. These communications, particularly the one-to-many ones, can be analyzed for a number of applications in domains such as economics, public policy and health. For these applications to be useful, at least two conditions have to be met. First, the data should be processed in real time or with low latency: this creates important algorithmic challenges in areas such as event detection, online classification/clustering, credibility/veracity assessment, among others. Second, the application designer must be well acquainted with the application domain, which is usually achieved by working in interdisciplinary teams. The lecture will introduce methods for processing social media data exemplifying through concrete applications, particularly in the areas of emergency response and disaster relief.