We can observe compelling reasons for developing a language that provides both, programming flexibility and structure. Numerous efforts to provide more practical programming languages have led to a variety of innovative developments. Fortran90 is now emerging as a powerful scientific programming language, incorporating some of the best features of F77 and C. Developments in the area of literate programming strive for both flexibility and structure. The notion of literate programming, that like is grouped with like, and that logical structure takes precedence over details, is in line with present trends to move towards object-oriented languages such as C++. Thus it is possible to write pseudo object-oriented code using literate programming methodologies. One example is FWEB, where multiple languages are supported within a single file (C, C++, F77, RATFOR, Fortran90, TeX, etc.) providing the greatest amount of flexibility to the programmer. (Look for the upcoming chapter on Literate Programming).