A number of the suggested apps were for social good, for example apps for improving sustainability and finding missing persons. Other apps were more lifestyle-oriented, for example for cooking and genealogy. A few were business focused, such as a brand marketing app and a point-of-sale system. Of course a couple were just plain ol' geeky, which we love too! You can find all 10 ideas below.

Missing Persons

Juan Sequeda, co-founder of Semantic Web Austin, has an idea for using linked data "to integrate data from displaced populations, specifically in Colombia." He references a BBC report from September 2009, about using semantic Web technology to enable people to search currently incompatible databases of missing persons in Columbia.

Sustainability

Bernard Vatant from Guillestre, France, wants to see "the Web of Data enable people anywhere in the world to find out smart, sustainable and low-cost solutions to their local development issues." For example, success stories in farming, water supply, energy, education and health "in environments similar to mine, anywhere in the world."

In short, Bernard wants a linked data equivalent to WiserEarth - an online community for people interested in sustainability.

A Better World

Aldo Bucchi from Chile wants an app to tackle "negligence, corruption and lack of accountability." Specifically he mentioned a recent 8.8 magnitude earthquake in Chile, which resulted in hundreds of deaths. Aldo believes that some of those deaths were avoidable, because of what he claims was "corruption and malpractice in the construction business." He thinks that a Web of data would help identify such things, as well as help "rebuild the country faster and in a more agile manner [with] the "loose-coupled coordination" that is naturally derived from a shared data substrate and a single world view."

Genealogy App

Sherry Main from Orange County, California would like an app for genealogy. Wrote Sherry:

"It would be amazing to be able to map and locate where your family is from, has been, and what notable events happened. If there was an application on a mobile device that pinged you when you are within a particular radius of say, my great-grandmother's birthplace, as I walked around a town, that would make real-world experiences more meaningful [...] As photos become geo-tagged going forward, imagine being able to get a push notification that showed an important family or historical photo to you as you stood or walked by that location."

Cooking App

Bart Stevens wants to be able to "select a (difficult) recipe and submit this to a service." He wants the following information back:

1. Where can I find the ingredients.

2. Place an order/make a reservation (@bakery, butcher or fish shop) for certain ingredients.

3. A route (street) map, per store.

4. Maybe a payment system.

Point-of-Sale & Inventory System

Daniel O'Connor would like to see a point-of sale-system and inventory system, for example for a small office supplies store.

He beckons us to imagine this: "I receive a new product, scan the barcode of it. My system queries the web for the supplier name, product data, etc [...] recognizes the supplier and hits their URI for the product. It assimilates all of the recommended price information (ie: good relations); depictions and populates my system." You can read the full scenario in his extended comment.

Brand Marketing

John Davidson suggests that linked data can be used to assist brand marketers, specifically to find out more about their customers. He offers this example:

"A customer becomes a fan of a popular hair care brand on Facebook. She separately opted-in on the brand site to receive email alerts for new products, promotional offers that she can redeem in stores, etc. Are these distinct, separate events or are they somehow connected? By integrating these streams from the "Web of Data" the brand marketer can understand that she is an advocate for their brand. She also has several dozen or more friends she regularly interacts with in social channels. The marketer can engage her with special offers to promote their cool new products with friends in her network. The subsequent buzz and chatter sends friends to their stores to buy the new hair care products and the cycle repeats."

Research Assistant

A comment on Georgi's blog suggests an app to review literature. "Professor Aloha" wrote that he/she would create an application that could "take any research topic and backtrace (through articles, dissertations, presentations, and their accompanying reference lists) all published research articles on that topic, sorting them by year of publication, author, country of origin, journal and major findings."

Enriched People Profiles

Atif Latif from Austria would like to build an aggregator for all of the possible resources related to a person on the Web. The end result, said Atif, "will be [a] highly semantified and enriched profile of a person." Atif is working on this as we speak, with a beta app named CAF-SIAL. Good luck Atif!

In a separate comment, Kingsley Idehen of semantic Web company OpenLink Software mentioned "Verifiable Identity," noting that "all databases (including the Web of Linked Data) need verifiable identity."

Website-less websites

Nathan suggested a number of things, our favorite being "Website-less websites". Nathan wrote that "when all the data is typed and in a single format (let's say rdf) then the need for websites and webpages can completely be disposed off, rather we can view the information in an array of clients side applications each with there own benefits (like we do currently with twitter clients), The entire web can theoretically and quite easily just be one big API."

Bruce Wayne of Factoetum wrote in a separate comment that he is developing "services that will have in impact in bringing about a Website-less web." He gives an example of a list of book titles.

Those are 10 suggestions from the ReadWriteWeb community. Perhaps some enterprising entrepreneurs or developers will pick up a few of these ideas for their next startup!

Georgi Kobilarov, who runs a Linked Data startup from Germany called Uberblic Labs, recently issued an interesting challenge on his blog. He asked: if we had a Web of Data, what would you build? Not to steal Georgi's thunder, but we think this is a great question to put to ReadWriteWeb readers too.

"If we had a Web of Data, I would built an application for painless travel planning. It would integrate flight plans, train timetables, bus routes, car rental offers, etc. And the user would be able to just say: I want to go from A to B: Find me the best/cheapest/fastest routes. [...] With a Web of Data, an application could do all that combining for me, the same way flight booking sites do that today for just flights."

Here's my idea for an app that uses the Web of Data. I'd like a web site or app that allows me to discover the locations of original art works by my favorite artists, and then create travel itineraries for me to see some or all of those art works (most famous artists have their art works scattered around the world, in various museums and galleries). It's possible that there is a web directory of artists somewhere that has some or even all of this data already, but if so I haven't found it.

I ask for this because every now and then I search the Web for a painting that I saw in a book. A recent example was a Modigliani painting that I was attempting to create a copy of, for my beginners acrylic painting class. The original painting was called "Portrait of Madame Hanka Zborowska." One of the results from Google told me that the original painting is located at the National Gallery of Modern Art, Rome, Italy.

I could potentially spend hours hunting down the locations of Modigliani's paintings, using Google - and it's likely that some of the data isn't currently online. So it would be great if I could query one web site or app: tell me where all the originals of Modigliani's paintings are in the world, and draw me an itinerary for visiting all or some of them. Heck, maybe even book my flights and hotels!

That's my example of what I'd build from a Web of Data. Now tell us what site or app you would like built, if the data was available on the Web.

Because it can't. It does not understand. It has no access to most sources. It lacks the semantic understanding and common sense to build bridges between information.

It is critical that machines gain a new level of understanding. Instead of statistically computing how well a search term matches a document, a machine must literally be able to understand. Therefore, knowledge bases are needed to look things up. Examples of these knowledge bases include:

• an encyclopedia containing knowledge to look up the semantic meaning and context of a particular term (e.g. to understand that Berlin is a city, how many people live there, and where it is),
• Yellow Pages or a service pool to query often-changing and more complex information (e.g. a route from Berlin to Porto by car, or the current temperature of Porto in Celsius),
• a people database to look up profile information, with user permissions, which could improve personalization and recommendations.

The Web of Data

The idea of the Web of Data originated with the Semantic Web. People tried to solve the problem of the inherent inability of machines to understand web pages. Initially, the aim of the Semantic Web was to invisibly annotate web pages with a set of meta-attributes and categories to enable machines to interpret text and put it in some kind of context. This approach did not succeed because the annotation was too complicated for humans who had no technical background. Similar approaches, like microformats, simplify the markup process and thus help bootstrap this chicken-egg problem.

These approaches have in common the effort to improve the machine-accessibility of knowledge on web pages that were designed to be consumed by humans. Furthermore, these sites contain a lot of information that is irrelevant to machines and that needs to be filtered. What is needed is a knowledge base for machines to look up "noiseless" information. But wait! Who said that machines and us humans need to share one web anyway?

The idea of the Web of Data came about as a result of both this limitation and the existence of countless structured data sets distributed all over the world and containing all kinds of information. These data sets are the property of companies that trend to make them accessible. Typically, a data set contains knowledge about a particular domain, like books, music, encyclopedic data, companies, you name it. If these data sets were interconnected (i.e. link to each other like websites), a machine could traverse this independent web of noiseless, structured information to gather semantic knowledge of arbitrary entities and domains. The result would be a massive, freely accessible knowledge base forming the foundation of a new generation of applications and services.

Linking Open Data

One promising approach is W3C's Linking Open Data (LOD) project. The above image illustrates participating data sets. The data sets themselves are set up to re-use existing ontologies such as WordNet, FOAF, and SKOS and interconnect them.

The data sets all grant access to their knowledge bases and link to items of other data sets. The project follows basic design principles of the World Wide Web: simplicity, tolerance, modular design, and decentralization. The LOD project currently counts more than 2 billion RDF triples, which is a lot of knowledge. (A triple is a piece of information that consists of a subject, predicate, and object to express a particular subject's property or relationship to another subject.) Also, the number of participating data sets is rapidly growing. The data sets currently can be accessed in heterogeneous ways; for example, through a semantic web browser or by being crawled by a semantic search engine.

To get a feeling of how this machine Web of Data feels like, you may want to look up:

• the company Yahoo! on CrunchBase,
• the city of Berlin or the game Tetris on DBpedia,
• the book iPhone: The Missing Manual on O'Reilly Media.

With every fact available on the Web of Data, more general and specific knowledge is made accessible to machines that will enable a whole new generation of services to be created. Highly sophisticated queries become machine-processable and accessible to the next generation of, say, search services.

Check out Tim Berners-Lee's talk at TED about the Web of Data. How do you think about it? Do you encounter the same issues being overloaded by information or too much noise?

(Photo by zorro-art. Graph by the Linking Open Data project.)