StatsD - Daemon for easy but powerful stats aggregation.
statsd-vis - Standalone StatsD server with built-in visualization.
OpenTracing - Vendor-neutral APIs and instrumentation for distributed tracing.
log.c - Simple logging library implemented in C99.
OpenTelemetry - Provides a single set of APIs, libraries, agents, and collector services to capture distributed traces and metrics from your application. (OpenTelemetry Specification)
Logstash - Transport and process your logs, events, or other data.
Fluent Bit - Fast Log Processor and Forwarder for Linux, Embedded Linux, MacOS and BSD.
GoAccess - Real-time web log analyzer and interactive viewer that runs in a terminal in *nix systems or through your browser.
Loglizer - Machine learning-based log analysis toolkit for automated anomaly detection.
DTXLoggingInfra - Logging infrastructure for Apple platforms.
Metrictank - Multi-tenant timeseries platform that can be used as a backend or replacement for Graphite.
EventNative - Open-source data collection framework.
Phuslu/Log - Structured Logging for Humans.
slog - Go library for capturing structured log information.
bunyan-rs - CLI to pretty print logs in bunyan format. A Rust port of the original JavaScript bunyan CLI.
Flog - Fake log generator for common log formats.
Logsuck - Easy log aggregation, indexing and searching.
Ekanite - High-performance syslog server with built-in text search.
OpenTelemetry Collector - Offers a vendor-agnostic implementation on how to receive, process and export telemetry data.