The ETL file extension is associated with Active Media Eclipse, a screen saver software for Windows, developed by Active Media. ETL file contains transition listing data. It should be a obsolete file type.
The ETL file extension is used by Microsoft Trace Log utility, a program that creates logs using the events from the kernel in Microsoft operating systems. ETL file includes binary log data at the trace level, and used to log high-frequency events while tracking the performance of an operating system.