7. Conclusion

This guide has presented concepts that define the World Wide Web, its evolution, semantic concepts, metadata, the Web of Data ecosystem, Web Semantic technologies, foundations underlying the concept of Linked Data and some of the most used reference vocabularies. Appendix A provides with some examples of software currently used in development environments to generate applications that manipulate Linked Data.

There was a time when the Web was a hot topic in some research fields, but had not yet been popularized and become an everyday technology. The Semantic Web is at an intermediate stage where some niches already capitalize on its potential, such as search engines and metadata embedded in pages of websites interested in being better understood by robots. The era of developing applications that will take advantage of this new model is only just beginning and will be key to the popularization of the Semantic Web. We are still in an increasingly intense stage of massive data publishing, but with a small number of applications. However, the importance of applications, or apps, as they are called, is quite obvious today in the world of mobile devices. When they want to catch a cab in a big city, many people naturally resort to published data harnessed by an application.

The guide ends with an extract from the book A Programmable Web: An Unfinished Work[91], by Aaron Swartz, one of the great web researchers and a defender of the idea of open data, who had some criticisms in relation to the Semantic Web vision, but also noted its chances for success:

“It’s easy to make fun of these kinds of visions. My father, upon seeing such demos, always used to ask, “But why does your toaster need to know about stock prices?” And perhaps, ultimately, they’re not worth all the effort. But the Semantic Web is based on bet, a bet that giving the world tools to easily collaborate and communicate will lead to possibilities so wonderful we can scarcely even imagine them right now. Sure, it sounds a little bit crazy. But it paid off the last time they made that gamble: We ended up with a little thing called the World Wide Web. Let’s see if they can do it again."