Mathematical calculator RionaCalc

RionaCalc is a simple but powerful calculator that works with arithmetic expressions. The major features of the program are:

supports more then 20 mathematical and logical operators and more than 40 functions
has built-in module for the units of measurement conversion
remembers upto 500 last expressions and results
two number formats
works with complex numbers, common fractions, date, time and stings
works with numbers in non-decimal scales of notation: binary, octal and hexadecimal numbers
solves the quadratic equation
finds root, minimum, maximum of the function and calculates value of define integral in any interval
unlimited number of user-defined variables
the possibility of adding your own functions using built-in programming language
can draw 2D and 3D graphics.

What is new in the last version:

Many improvements in Graph-2D window
Fixed: calculator crashed after trying calculate lcm(0;0) or gcd(0;0)
New: added random number generator (Mersenne Twister) and two functions: randinit - initialise random number generator, rand - generate the next random number
New: added in main menu item for calling Graph2D window: Tools->Graph 2D