JFormula is a java library for evaluating various mathematical expressions. User can evaluate instantly a string setting variables, adding its own functions or operators. JFormula works with string, boolean, double, BigDecimal and List. It works in a high and medium precision mode. Unicode characters are managed. "IF THEN ELSE" expressions can be used. There are by default 24 mathematical functions and 30 operators. A formula can have one or several expression lines like A=... 2A+2B. JFormula is JDK 1.1 until 1.5 compliant. JFormula is used by EADS "Space transportation".