It’s not the oldest shipper of this list (that would be syslog-ng, ironically the only one with «new» in its name), it’s certainly the best known. That’s because it has lots of plugins: inputs, codecs, filters and outputs. Basically, you can take pretty much any kind of data, enrich it as you wish, then push it to lots of destinations. Logstash’s main strongpoint is flexibility, due to the number of plugins. Also, its clear documentation and straightforward configuration format means it’s used in a variety of use-cases. This leads to a virtuous cycle: you can find online recipes for doing pretty much anything. Here are a few examples from us: 5 minute intro, reindexing data in Elasticsearch, parsing Elasticsearch logs, rewriting Elasticsearch slowlogs so you can replay them with JMeter.