NumWorks - The graphing calculator that makes learning math easier.
SpeQ Mathematics - SpeQ is a small, extensive mathematics program with a simple, intuitive interface.
Learney - Knowledge aggregator for developers
Qalculate! - Qalculate! is a multiplatform multi-purpose desktop calculator.
eMathHelp.net - Site is created to help people learn math. Includes algebra, calculus, differential equation calculators and notes with many examples.
Paperspade - Type math easily through just English text!