The Jejak trace framework is a framework for injecting probes into Smalltalk methods, and record their execution. It can record an execution to the smallest detail (all calls, all values, all assignments), that over a long sequence (hundreds or thousands of calls), and let one navigate freely through the recorded trace along with the traced source code. It is capable of tracing system, startup or display methods, without interruption or blocking the overall image, allowing for very fine non-intrusive system analysis.
Version 1 requires the Opal Compiler and integrates into OmniBrowser (Pharo 1.4). The latest version is integrated in Pharo 2.0 and the Alt Browser.