TotalView [
1] is a high-end Unix-oriented debugger that's particularly important to those working on parallelization. Its
scripting language, rather remarkably, is
Tcl.
What is TotalView? [
2]
TotalView is a sophisticated software debugger product from Rogue Wave Software, Inc.
...and before that, TotalView Technologies, LLC (2007-2009)
...and before that, Etnus LLC. (1998-2007)
...and before that, Dolphin Interconnect Solutions, Inc. (1996-1998)
...and before that, BBN Systems and Technologies, a division of BBN Corporation (1993-1996)
Used for debugging and analyzing both serial and parallel programs.
Especially designed for use with complex, multi-process and/or multi-threaded applications.
Without question, the most popular HPC debugger to date.

I used Totalview while at BBN - best debugger I've used. To bad no Windows version