CONTIN: A general purpose constrained regularization program for inverting noisy linear algebraic and integral equations. Applications: Inversion of data represented by linear algebraic or integral equations, such as general analysis of multi-exponential decay (Laplace inversion) or estimating secondary structure from circular dichroism; Most aspects of the problem can be easily modified in small user-oriented modules; too many applications to list here have been implemented by users; Running in hundreds of laboratories with a wide variety of computers.