In this chapter, I presented techniques for assessing and exploiting features of web sites that make them amenable to mashups. Specifically, you looked at web sites from the point of view of an end user. I presented a list of questions to use in analyzing web sites. Key questions include the following: What are the main resources and their URLs? How is the public being used in mashups? Does the site use tags, feeds, and weblogging features? What are the data formats for importing and exporting data? You applied these questions briefly when revisiting the mashups from the previous chapter.

The bulk of this chapter is devoted to studying URL languages of web sites and their importance in making mashups. Specifically, I presented an extensive analysis of Flickr, which has a rich URL language that covers a large part—but not all—of Flickr’s functionality. I presented a simple pattern for creating that exploits the URL languages (the Mashup-­by-URL-Templating-and-Embedding pattern) to create a mashup between Flickr and WordPress. I continued my examination of URL languages with a study of Google Maps, Amazon, and del.icio.us. I concluded the chapter with a discussion of screen-­scraping and bots and how they can be used when public APIs are not available.

You’ll turn in the next chapter to looking in depth at one group of issues raised in this chapter: tagging and folksonomies, their relationship to formal taxa, and how they can be used to knit together elements within and across sites.