System Logger is an object logger (by opposition to textual logger).
It was developed as a logger for Pharo. The community chose Beacon which proposes an alternative design. Still you may want to use SystemLogger. Check the documentation.
SystemLogger proposes a Pharo solution that focuses on objects. The central concept is the Log object which represents a single logging event. The event can be specialized via subclassing with various types of events. Similar to Toothpick, it features a central object that collects log objects, and has several concrete loggers that consume the log objects through various bindings such as the standard output or a database. The size is also rather tiny, the core containing some 535 lines of code. Like in other logging frameworks, you can specify both levels of severity and tags that can be used for filtering.
The following script installs it in Pharo.
Metacello new
baseline: 'SystemLogger';
repository: 'github://Ducasse/SystemLogger/src';
load.
Add the following code to your Metacello baseline or configuration
spec
baseline: 'SystemLogger'
with: [ spec repository: 'github://Ducasse/SystemLogger/src' ].