Equation (1.2-9) is a second order, nonlinear, vector, differential equation which has defied solution in its present form. It is here therefore we depart from the realities of nature to make some simplifying assumptions...
Roger R. Bate, Jerry E. White, and Donald MuellerFundamentals of Astrodynamics, 1971
By now you should be confident in your understanding of both RSS and Atom, how the standards work, how to parse them, and how to fit them into the rest of the Internet. Before we finish this book with an explanation of how the standards can be extended, we have a good opportunity to show our knowledge in action. This chapter, therefore, is a collection of recipes for creating and using feeds that do things slightly more interesting and useful than simply transporting headlines and articles.