Lyapunov exponent and bit strings

I was hoping that someone could instruct me on Lyapunov exponents.
1. How this metric relates to bit strings
2. Software that might be freely avaiable on a PC (standard c- language
funstions only or PC based executable) to compute the Lyapunov exponents for
bit strings
3. How the results are normallay interpreted for the said bits strings (I.E.
what information is normally obtained from the results)

Thank you so much.