tscat is a simple filter that reads line from standard input, prepends a timestamp to each line, and writes to standard output. Timestamps can be absolute (current time of day), relative to process start time, or deltas since the previous line (previous timestamp).
The current version is tscat-1.0.tar.gz (19 Feb 2006).
For build and installation instructions, see the README file.
For usage, see the man page.