Vegeta is a versatile HTTP load testing tool and Go library. It simulates constant-rate or oscillating traffic against HTTP endpoints, collects latency and byte metrics, and generates reports (text, JSON, histograms, HTML plots). The core is an attack engine with pluggable pacers, a targeter for reading HTTP request specs, and a metrics pipeline using t-digest for percentile estimates. It includes a Prometheus exporter and a downsampling library for plotting large time series. The codebase is well-structured with clean package boundaries, cross-platform support, and extensive testing including fuzzing.