SMath Studio - Tiny, powerful, free mathematical program with WYSIWYG editor and complete units of measurements support.
Wabbitemu - Wabbitemu is an accurate emulator for Texas Instruments based calculators TI-73 to TI-86.
PTC Mathcad - PTC Mathcad PTC Mathcad is Engineering Math Software That Allows You to Perform, Analyze, and Share Your Most Vital Calculations.
CEmu TI 84+ CE Emulator - Emulates the TI 84+ CE and TI 83 Premium CE calculators from a ROM dump from a real calculator.
MATLAB - A high-level language and interactive environment for numerical computation, visualization, and programming
TI Connect CE - Computer software that allows for connectivity between your computer and TI-84 Plus family graphing calculator.