A discussion on finding free software for fitting data into a four-parameter equation, specifically the generalized logistic function, highlights several options. While TableCurve is noted for its capabilities, it is not free. Users are directed to a resource for selecting curve fitting packages based on operating system and ratings, which offers a variety of free or shareware options. Additionally, methods for fitting data using the generalized logistic function can be found in a specific document. Python's scipy module is recommended for performing curve fitting, with resources available online for guidance. The conversation also mentions the CurveFit Tracer tool, which may assist in converting graph images into usable mathematical equations, particularly for vacuum tube operating curves.