From the developer: ?RF21 is an enhanced scientific calculator that allows for permanent installation of a user's own functions, applications and libraries. User functions can have one or many arguments and values. It's a programming system at the same time - and an archive capable of holding a lifetime's mathematical work, with comments attached to each function, grouped in theme oriented library files. An integrated searchable database helps find material that you created years ago. Each function will self-reassemble when its name is called, be it for one-time use or from within a newly created user function. Standard numeric features can be applied to all formulae and functions. Predefined functions include the gamma, zeta and psi-functions, Euler and Bernoulli numbers, elliptic integrals, cumulative Binomial distribution and more. Sample libraries containing applications such as: eigen values, characteristic polynomials, Keplerian orbits, geodesic travel routes, diophantic problems, partition numbers, combinatorics and stochastics. Comprehensive written documentation available from the author's homepage. This version 0.84 for Windows98 adds functionality to its predecessor version 0.81, which is a 32 bit DOS program and still available from the author's homepage.?