E-Tesla6 - The next version of E-Tesla that uses the latest secondary voltage profile data from Paul Nicholson's TSPP project. This program predicts the resonant frequency of a secondary coil and top load given the physical dimensions of the secondary and toroid.
E-Tesla5 - The older version of E-Tesla.
TeslaPro - A simple Tesla coil parameter calculator
MMCCalc2 - A program to determine the most economical MMC for a given coil
MandKV31 and the PDF file - A great program Mark Rzeszotarski made to determine primary to secondary coupling. Extremely accurate and easy to use.
TCplan.zip Kurt Schraner's super powerful Excel program for figuring out just about anything with Tesla coils. It has E-Tesla and other modern programs imbedded in it.
MicroSim
8.0 Demo Version(16Mb) - The best circuit simulator out there
and the standard for Tesla coil modeling
Instructions
to MicroSim(4.5Mb PDF)
Version 9.1 of MicroSim (27Mb) - Much like the older version