To illustrate the wide field of research conducted in the Stieltjes Institute, in this chapter a research `highlight' from each of the four main areas is presented.

For **Algebra and Geometry**, J.-H. Evertse, senior researcher at the University of Leiden and member of the programme `Number Theory' has contributed a paper on `Diophantine Equations and Diophantine Approximation'.

For **Analysis**, A. Doelman, professor at the University of Amsterdam and leader of the programme `Differential Equations, Dynamical Systems and Numerical Analysis' discusses the topic `Stabilization of pulses by diffusion'.

**Stochastics** is represented W.Th.F. den Hollander, leader of the programme `Probability' and professor at the Eindhoven University of Technology as well as scientific director of EURANDOM, with a paper named `Fluctuations of the Wiener Sausage'.

For **Operations Research** such a highlight is `The Mathematics of Call Centers' by G. Koole, professor at the Free University of Amsterdam and leader of the programme `Stochastic Operations Research'.