ThunderBolt is a logger extension for ActionScript 2 and 3 as well as Flex 2 and 3 applications based on the Firebug add-on for Firefox.
It looks very promising, and knowing Jens Krause’s ordinary high level of ingenuity and as well as quality, I am willing to give it a shot.
* Detailed information (class, file, line number, time, frame)
* Log levels (info, warning, error, fatal)
* Interactive tree view for complex object structures
* Profiling (time spend during code execution)
* Collapsible grouped output
* Filter log by classes and packages
* Interactive console (inspect and modify object on runtime)
* Log levels: INFO, WARN, ERROR, DEBUG (FATAL, ALL)
* Tree view for complex object structures such as class identifier and its properties
* Custom LogTarget based on Flex Logging API including filters
* memory snapshot
* stop logging flag
* SWC components for logging using Flex 2/3 or Flash CS3