Field-tested open source data analytics system used and trusted all around the world. Search your logs, create charts, send reports and be alerted when something happens. All running on the existing JVM in your datacenter.

logstash is a tool for managing events and logs. You can use it to collect logs, parse them, and store them for later use (like, for searching). Speaking of searching, logstash comes with a web interface for searching and drilling into all of your logs.

visualize logs and time-stamped data Elasticsearch works seamlessly with Kibana to let you see and interact with your data

MyLogPHP, a single class to generate log files in PHP. This class allow programmers to easily write messages to a log file.

KLogger is an easy-to-use logging class for PHP. It supports standard log levels like debug, info, warn, error, and fatal. Additionally, it isn't naive about file permissions (which is expected). It was meant to be a class that you could quickly include into a project and have working right away.

Monolog sends your logs to files, sockets, inboxes, databases and various web services. See the complete list of handlers below. Special handlers allow you to build advanced logging strategies.

pgFouine is a PostgreSQL log analyzer used to generate detailed reports from a PostgreSQL log file. pgFouine can help you to determine which queries you should optimize to speed up your PostgreSQL based application.

lumberjack is an open-source project to update and enhance the event log architecture. lumberjack aims to improve the creation and standardize the content of event logs by implementing the concepts and specifications proposed by the Common Event Expression (CEE).