 He emphasized the inability of OOP to model time properly, which is getting increasingly problematic as software systems become more concurrent.Eric S. Raymond, a Unix programmer and open-source software advocate, has been critical of claims that present object-oriented programming as the "One True Solution", and has written that object-oriented programming languages tend to encourage thickly layered programs that destroy transparency.Raymond compares this unfavourably to the approach taken with Unix and the C programming language.