  The Web has been around and maturing for 25 years. The popular websites of
today have undergone vast changes during this period, with a few being there
almost since the beginning and many new ones becoming popular over the years.
This makes it worthwhile to take a look at how these sites have evolved and
what they might tell us about the future of the Web. We therefore embarked on a
longitudinal study spanning almost the whole period of the Web, based on data
collected by the Internet Archive starting in 1996, to retrospectively analyze
how the popular Web as of now has evolved over the past 18 years.
  For our study we focused on the German Web, specifically on the top 100 most
popular websites in 17 categories. This paper presents a selection of the most
interesting findings in terms of volume, size as well as age of the Web. While
related work in the field of Web Dynamics has mainly focused on change rates
and analyzed datasets spanning less than a year, we looked at the evolution of
websites over 18 years. We found that around 70% of the pages we investigated
are younger than a year, with an observed exponential growth in age as well as
in size up to now. If this growth rate continues, the number of pages from the
popular domains will almost double in the next two years. In addition, we give
insights into our data set, provided by the Internet Archive, which hosts the
largest and most complete Web archive as of today.
