Kris Buytaert gave a talk on open source monitoring tools. He discussed how monitoring used to be an afterthought but new tools now focus on automation and integration. Popular modern tools like Prometheus focus on metrics collection and short-term storage while shipping long-term data to systems like Graphite. Prometheus excels at containerized environments through scraping but can also monitor other systems. Visualization and alerting have many options like Grafana, Icinga, and AlertManager. The landscape continues evolving towards full observability of applications and services.