Python

http://www.python.org

"Python is an interpreted, interactive, object-oriented programming language. It is often compared to Tcl, Perl, Scheme or Java"

wxPython

http://wxpython.org/

"... a blending of the wxWidgets C++ class library with the Python programming language"

Boa Constructor

http://boa-constructor.sourceforge.net/

"Boa Constructor is a cross platform Python IDE and wxPython GUI Builder. It offers visual frame creation and manipulation, an object inspector, many views on the source like object browsers, inheritance hierarchies, doc string generated html documentation, an advanced debugger and integrated help"

General

Threads - http://www.python.org/doc/current/lib/module-thread.html

Stopwatch - http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/124894