pacecalc.tcl
a pace and calorie calculator for runners.
Released according to the Gnu Public License v. 3 or later.
by Tony Baldwin
http://wiki.tonybaldwin.info

pacecalc can calculate

*  calories burned for carrying your carcass over any distance (only for miles, though…haven't worked the math for metric measures).
*  Your pace if you run $distance in $time
*  Your total time if you run $distance at $pace

Handy for planning training or races, dieting, etc.

Cross-platform Win/Lin/Mac
Requires Tcl/Tk 
(gnu/linux folks, install tcl with your distribution's package manager.
win/mac folks, get it here: http://www.activestate.com/activetcl )

Installation:
Linux/Mac - run the install.sh script.
Windows - just stick the pacecalc.exe file anywhere and click on it to run it.
You can make a desktop shortcut to it.
Heck, you can put it on your Desktop

Also packaged as part of TclRunlog
http://tonyb.us/tclrunlog