Windows Reactance and Resonance Calculator.     For some time I have been wanting a reactance and resonance calculator and now I have one.  There are probably a dozen others out there, I haven't looked.

It is built in National Instruments Lab Windows and operates under Windows XP and 7 32 and 64 bit.  It may work under other versions, however I haven't tried it.  If you would like to try it

Downlad Windows Reactance and Resonance Calculator

Windows Units Conversion Calculator.     I have been using a number of references in those cases where I needed to make a units conversion.  That was rather cumbersome so I wrote a windows application in National Instruments Lab Windows to make a good many converstions.

Calculate 1% Resistor Values in Mathcad  I have found this very useful over the years.  Given a calculated resistor value, it returns the nearest 1% standard value.