Kingsley Idehen's Blog Data Space

In response to the "Semantic Web Technology" application classification scheme espoused by ReadWriteWeb (RWW), emphasized in the post titled: Where are all the RDF-based Semantic Web Apps?, here is my attempt to clarify and reintroduce what OpenLink Software offers (today) in relation to Semantic Web technology.

From the RWW Top-Down category, which I interpret as: technologies that produce RDF from non RDF data sources. Our product portfolio is comprised of the following; Virtuoso Universal Server, OpenLink Data Spaces, OpenLink Ajax Toolkit, and OpenLink Data Explorer (which includes ubiquity commands).

Virtuoso Universal Server functionality summary:

1. Generation of RDF Linked Data Views of SQL, XML, and Web Services in general
2. Deployment of RDF Linked Data
3. "On the Fly" generation of RDF Linked Data from Document Web information resources (i.e. distillation of entities from their containers e.g. Web pages) via Cartridges / Drivers
4. SPARQL query language support
5. SPARQL extensions that bring SPARQL closer to SQL e.g Aggregates, Update, Insert, Delete Named Graph support (i.e. use of logical names to partition RDF data within Virtuoso's multi-model dbms engine)
6. Inference Engine (currently in use re. DBpedia via Yago and UMBEL)
7. Host and exposes data from Drupal, Wordpress, MediaWiki, phpBB3 as RDF Linked Data via in-built support for PHP runtime
8. Available as an EC2 AMI
9. etc..

OpenLink Data Spaces functionality summary:

1. Simple mechanism for Linked Data Web enabling yourself by giving you an HTTP based User ID (a de-referencable URI) that is linked to a FOAF based Profile page and OpenID
2. Binds all your data sources (blogs, wikis, bookmarks, photos, calendar items etc. ) to your URI so can "Find" things by only remembering your URI
3. Makes your profile page and personal URI the focal point of Linked Data Web presence
4. Delivers Data Portability (using data access by value or data access by reference) across data silos (e.g. Web 2.0 style social networks)
5. Allows you make annotations about anything in your own Data Space(s) on the Web without exposure to RDF markup
6. A Briefcase feature that provides a WebDAV driven RDF Linked Data variant of functionality seen in Mac OS X Spotlight and WinFS with the addition of SPARQL compliance
7. Automatically generates RDFa in its (X)HTML pages
8. Blog, Wiki, WebDAV File Server, Shared Bookmarks, Calendar, and other applications that look and feel like Web 2.0 counterparts but emitt RDF Linked Data amongst a plethora of data exchange formats
9. Available as an EC2 AMI
10. etc..

OpenLink Ajax Toolkit functionality summary:

1. Provides binding to SQL, RDF, XML, and Web Services via Ajax Database Connectivity Layer (you only need an ODBC, JDBC, OLE-DB, ADO.NET, XMLA Driver, or Web Service on the backend for dynamic data access from Javascript)
2. All controls are Ajax Database Connectivity bound (widgets get their data from Ajax Database Connectivity data sources)
3. Bundled with Virtuoso and ODS installations.
4. etc.

OpenLink Data Explorer functionality summary

1. Distills entities associated with information resource style containers (e.g. Web Pages or files) as RDF Linked Data
2. Exposes the RDF based Linked Data graph associated with information resources (see the Linked Data behind Web pages)
3. Ubiquity commands for invoking the above
4. Available as a Hosted Service or Firefox Extension
5. Bundled with Virtuoso and ODS installations
6. etc.

Note:

Of course you could have simply looked up OpenLink Software's FOAF based Profile page (*note the Linked Data Explorer tab*), or simply passed the FOAF profile page URL to a Linked Data aware client application such as: OpenLink Data Explorer, Zitgist Data Viewer, Marbles, and Tabulator, and obtained information. Remember, OpenLink Software is an Entity of Type: foaf:Organization, on the burgeoning Linked Data Web :-)

Related

• Linked Data Planet Keynote (RDFa based remix edition)
• On The Cusp: A Global Review of the Semantic Web Industry.

This post is in response to Glenn McDonald's post titled: Whole Data, where he highlights a number of issues relating to "Semantic Web" marketing communications and overall messaging, from his perspective.

By coincidence, Glenn and I presented at this month's Cambridge Semantic Web Gathering.

I've provided a dump of Glenn's issues and my responses below:

Issue - RDF

• Ingenious data decomposition idea, but:
• too low-level; the assembly language of data, where we need Java or Ruby
• "resource" is not the issue; there's no such thing as "metadata", it's all data; "meta" is a perspective
• lists need to be effortless, not painful and obscure
• nodes need to be represented, not just implied; they need types and literals in a more pervasive, integrated way.

Response:

RDF is a Graph based Data Model it stands for Resource Description Framework. The Metadata data angle comes from it's Meta Content Framework (MCF) origins. You can express and serialize data based on the RDF Data Model using: Turtle, N3, TriX, N-Triples, and RDF/XML.

Issue - SPARQL (and Freebase's MQL)

These are just appeasement:
- old query paradigm: fishing in dark water with superstitiously tied lures; only works well in carefully stocked lakes
- we don't ask questions by defining answer shapes and then hoping they're dredged up whole.

Response:

SPARQL, MQL, and Entity-SQL are Graph Model oriented Query Languages. Query Languages always accompany Database Engines. SQL is the Relational Model equivalent.

Issue - Linked Data

Noble attempt to ground the abstract, but:
- URI dereferencing/namespace/open-world issues focus too much technical attention on cross-source cases where the human issues dwarf the technical ones anyway
- FOAF query over the people in this room? forget it.
- link asymmetry doesn't scale
- identity doesn't scale
- generating RDF from non-graph sources: more appeasement, right where the win from actually converting could be biggest!

Response:

Innovative use of HTTP to deliver "Data Access by Reference" to the Linked Data Web.

When you have a Data Model, Database Engine, and Query Language, the next thing you need is a Data Access mechanism that provides "Data Access by Reference". ODBC and JDBC (amongst others) provide "Data Access by Reference" via Data Source Names. Linked Data is about the same thing (URIs are Data Source Names) with the following differences:

• Naming is scoped to the entity level rather than container level
• HTTP's use within the data source naming scheme expands the referencability of the Named Entity Descriptions beyond traditional confines such as applications, operating systems, and database engines.

Issue - Giant Global Graph

Hugely motivating and powerful idea, worthy of a superhero (Graphius!), but:
- giant and global parts are too hard, and starting global makes every problem harder
- local projects become unmanageable in global context (Cyc, Freebase data-modeling lists...). And my thus my plea, again. Forget "semantic" and "web", let's fix the database tech first:
- node/arc data-model, path-based exploratory query-model
- data-graph applications built easily on top of this common model; building them has to be easy, because if it's hard, they'll be bad
- given good database tech, good web data-publishing tech will be trivial!
- given good tools for graphs, the problems of uniting them will be only as hard as they have to be.

Response:

Giant Global Graph is just another moniker for a "Web of Linked Data" or "Linked Data Web".

Multi-Model Database technology that meshes the best of the Graph & Relational Models exist. In a nutshell, this is what Virtuoso is all about and it's existed for a very long time :-)

Virtuoso is also a Virtual DBMS engine (so you can see Heterogeneous Relational Data via Graph Model Context Lenses). Naturally, it is also a Linked Data Deployment platform (or Linked Data Sever).

The issue isn't the "Semantic Web" moniker per se., it's about how Linked Data (foundation layer of Semantic Web) gets introduced to users. As I said during the MIT Gathering: "The Web is experienced via Web Browsers primarily, so any enhancement to the Web must be exposed via traditional Web Browsers", which is why we've opted to simply add "View Linked Data Sources" to the existing set of common Browser options that includes:

1. View page in rendered form (default)
2. View page source (i.e., how you see the markup behind the page)

By exposing the Linked Data Web option as described above, you enable the Web user to knowingly transition from the traditional Rendered (X)HTML page view to the Linked Data View (i.e., structured data behind the page). This simple "User Interaction" tweak makes the notion of exploiting a Structured Web becomes somewhat clearer.

The Linked Data Web isn't a panacea. It's just an addition to the existing Web that enrichens the things you can do with the Web. It's predominance, like any application feature, will be subject to the degrees to which it delivers tangible value or matrializes internal and external opportunity costs.

Note: The Web isn't ubiquitous today becuase all it's users groked HTML Markup. It's ubquitity is a function of opportunity costs: there simply came a point in the Web boostrap when nobody could afford the opportunity costs associated with being off the Web. The same thing will play out with Linked Data and the broader Semantic Web vision.

1. Linked Data Journey part of my Linked Data Planet Presentation Remix(from slides 15 to 22 - which include bits from TimBL's presentation)
2. OpenLink Data Explorer
3. OpenLink Data Explorer Screenshots and examples.

Yikes! I've just discovered that the final part of the semanticweb.com's interview with Jim Hendler and I, includes critical paragraphs that omit my example links :-( As you can imagine, this is a quite excruciating, bearing in mind that "Literals" are of marginal value in a Linked Data world.

Anyway, thanks to the Blogosphere, I can attempt to fix this problem myself -- via this post :-)

Q. If you wanted to provide a bewildered but still curious novice a public example of Linked Data at work in their everyday life, what would it be?

Kingsley Idehen: Any one of the following:

My Linking Open Data community Profile Page - the Linked Data integration is exposed via the "Explore Data" Tab My Linked Data Space - viewed via OpenLink's AJAR (Asynchronous Javascript and RDF) based Linked Data Brower My Events Calendar Tag Cloud - a Linked Data view of my Calendar Space using an RDF-aware browser In all cases, you have the ability to explore my data spaces by simply clicking on the links, which on the surface appear to be standard hypertext links, although in reality you are dealing with hyperdata links (i.e., links to entities that result in the generation of entity description pages that expose entity properties via hyperdata links). Thus, you have a single page that describes me in a very rich way since it encompasses all data associated with me, covering: personal profile, blog posts, bookmarks, tag clouds, social networks etc.

Q. What would you show the CEO or CTO of a company outside the tech industry?

Kingsley Idehen: A link to the Entity ALFKI, from the popular Northwind Database associated with Microsoft Access and SQL Server database installations. This particular link exposes a typical enterprise data space (orders, customers, employees, suppliers ...) in a single page. The hyperdata links represent intricate data relationships common to most business systems that will ultimately seek to repurpose existing legacy data sources and SOA services as Linked Data. Alternatively, I would show the same links via the Zitgist Data Viewer (another Linked Data-aware browser). In both cases, I am exploiting direct access to entities via HTTP due to the protocols incorporation into the Data Source Naming scheme.

- Produce RDF Linked Data from non RDF Data Sources (Heterogeneous SQL, XML, Web Services)

- Provide highly scalable RDF Data Management via a Quad Store (DBpedia is an example of a live demonstration)

- Sophisticated Deployment of Linked Data that exploits the power of SPARQL

- Powerful WebDAV innovations that simplify read-write mode interaction with Linked Data

- Use Web Data Virtualization to address the pain and frustration associated with Web Data Silos (e.g. OpenLink Data Spaces layer stop Virtuoso that delivers Personal Data Spaces / Unified Storage in the Clouds)

- Deliver a Linked Data development and deployment platform to .NET (VB, C#) , Java, PHP, Ruby, Perl, Python, 'C', C++, and other developers

- More...

Daniel lewis has penned a variation of post about Linked Data enabling PHP applications such as: Wordpress, phpBB3, MediaWiki etc.

Daniel simplifies my post by using diagrams to depict the different paths for PHP based applications exposing Linked Data - especially those that already provide a significant amount of the content that drives Web 2.0.

If all the content in Web 2.0 information resources are distillable into discrete data objects endowed with HTTP based IDs (URIs), with zero "RDF handcrafting Tax", what do we end up with? A Giant Global Graph of Linked Data; the Web as a Database.

So, what used to apply exclusively, within enterprise settings re. Oracle, DB2, Informix, Ingres, Sybase, Microsoft SQL Server, MySQL, PostrgeSQL, Progress Open Edge, Firebird, and others, now applies to the Web. The Web becomes the "Distributed Database Bus" that connects database records across disparate databases (or Data Spaces). These databases manage and expose records that are remotely accessible "by reference" via HTTP.

As I've stated at every opportunity in the past, Web 2.0 is the greatest thing that every happened to the Semantic Web vision :-) Without the "Web 2.0 Data Silo Conundrum" we wouldn't have the cry for "Data Portability" that brings a lot of clarity to some fundamental Web 2.0 limitations that end-users ultimately find unacceptable.

In the late '80s, the SQL Access Group (now part of X/Open) addressed a similar problem with RDBMS silos within the enterprise that lead to the SAG CLI which is exists today as Open Database Connectivity.

In a sense we now have WODBC (Web Open Database Connectivity), comprised of Web Services based CLIs and/or traditional back-end DBMS CLIs (ODBC, JDBC, ADO.NET, OLE-DB, or Native), Query Language (SPARQL Query Language), and a Wire Protocol (HTTP based SPARQL Protocol) delivering Web infrastructure equivalents of SQL and RDA, but much better, and with much broader scope for delivering profound value due to the Web's inherent openness. Today's PHP, Python, Ruby, Tcl, Perl, ASP.NET developer is the enterprise 4GL developer of yore, without enterprise confinement. We could even be talking about 5GL development once the Linked Data interaction is meshed with dynamic languages (delivering higher levels of abstraction at the language and data interaction levels). Even the underlying schemas and basic design will evolve from Closed World (solely) to a mesh of Closed & Open World view schemas.

OpenLink Software are pleased to announce release 2.6 of the OpenLink AJAX Toolkit (OAT).

New Semantic Data Web related features and enhancements include:

* A Javascript-based Fresnel processor enabling declarative RDF-based display templates for RDF Data Sources

* An XSLT template for generating HTML pages from the Fresnel processor's XML output

* Interactive Query Builder for SPARQL (iSPARQL). This version of the iSPARQL application includes support for INSERTs and DELETEs

* Enhanced Javascript-based N3/Turtle parser

* New Navigator viewer panel for RDF Browser.

*Project Home Page

*Source Code

*Live Features Demonstrations.

The Recent security Ajax security alert have attracted comments from:

Shelley Powers via her post titled: More Ajax Security and many others.

In anticipation of the obvious concerns of many Javascript based developers, Ondrej Zara (lead developer of the OpenLink Ajax Toolkit) has written a post titled: OAT and JS Hijacking, that explains the security aspects our Javascript Toolkit in relation to this alert

Frederick Giasson penned an interesting post earlier today that highlighted the RDF Middleware services offered by Triplr and the Virtuoso Sponger

Some Definitions (as per usual):

RDF Middleware (as defined in this context) is about producing RDF from non RDF Data Sources. This implies that you can use non RDF Data Sources (e.g. (X)HTML Web Pages, (X)HTML Web Pages hosting Microformats, and even Web Services such as those from Google, Del.icio.us, Flickr etc..) as Semantic Web Data Source URIs (pointers to RDF Data).

In this post I would like to provide a similar perspective on this ability to treat non RDF as RDF from RDF Browser perspective.

First off, what's an RDF Browser?

An RDF Browser is a piece of technology that enables you to Browse RDF Data Sources by way of Data Link Traversal. The key difference between this approach and traditional browsing is that Data Links are typed (they possess inherent meaning and context) whereas traditional links are untyped (although universally we have been trained to type them as links to Blurb in the form of (X)HTML pages or what is popularly called "Web Content".).

There are a number of RDF Browsers that I am aware off (note: pop me a message directly of by way of a comment to this post if you have a browser that I am unaware of), and they include (in order of creation and availability):

1. Tabulator
2. DISCO - Hyperdata Browser
3. OpenLink Ajax Toolkit's RDF Browser (a component of the OAT Javascript Toolkit)

Each of the browsers above can consume the services of Triplr or the Virtuoso Sponger en route to unveiling a RDF Data that is traversable via URI dereferencing (HTTP GETing the data exposed by the Data Pointer). Thus you can cut&paste the following into each of the aforementioned RDF Browsers:

1. Triplr's RDF Data (Triples) extractions from Dan Connolly's Home Page
2. The Virtuoso Sponger's RDF Data (Triples) extractions from Dan Connolly's Home Page

Since we are all time challenged (naturally!) you can also just click on these permalinks for the OAT RDF Browser demos:

1. Permalink for Triplr's RDF Data (Triples) extractions from Dan Connolly's Home Page
2. Permalink for the Virtuoso Sponger's RDF Data (Triples) extractions from Dan Connolly's Home Page

Linking personal posted content across communities: "

With the help of Kingsley, Uldis and I have been looking at how SIOC can be used to link the content that a single person posts to a number of community sites. The picture below shows an example of stuff that I’ve created on Flickr, YouTube, etc. through my various user identities on those sites (these match some SIOC types that we want to add to a separate module). We can also say that each Web 2.0 content item is a user-contributed post, with some attached or embedded content (e.g. a file or maybe just some metadata). This is part of a new discussion on the sioc-dev mailing list, and we’d value your contributions.

Edit: The inner layer is a person (semantically described in FOAF), the next layer is their user accounts (described in FOAF, SIOC) and the outer layer is the posted content - text, files, associated metadata - on community sites (again described using SIOC).

No Tags"

(Via John Breslin - Cloudlands.)

The point that John is making about the Data Web and Interlinked Data Spaces exposed via URIs (e.g Personal URIs), crystallizes a number of very important issues about the Data Web that may remain unclear. I am hoping that by digesting the post excerpt above, in conjunction with the items below, aids the pursuit of clarity and comprehension about the all important Data Web (Semantic Web - Layer 1):

1. Your OpenID can be Your Personal URI (as noted by Henry Story's post about: The Many Uses of OpenID). That that's what I have courtesy of OpenLink Data Spaces (ODS)
2. The above only works unobtrusively (i.e. OpenID and Personal sharing a URI) if Content Negotiation is exploited on the Client and Server sides.
3. TimBL's call out to Share Your Data and Link to Other Data via URIs via post titled: Give Yourself a URI.
4. W3C's Best Practice Recipes for Publishing RDF Vocabularies
5. W3C's Architecture of the World Wide Web - Vol 1 which covers URI Dereferencing (HTTP GET-ing the data that a URI points to)
6. Richard Cyganiak's post titled: Debugging Semantic Web Sites with Curl.

Examples of some of these principles in practice:

1. Chris Bizer, Tobias Gaub, and Richard's Javascript based Semantic Web Client Library
2. DISCO RDF Browser
3. OpenLink Ajax Toolkit's (OAT) RDF Browser
4. OpenLink Interactive SPARQL Query by Example (iSPARQL QBE)
5. Dynamic Data Web Pages from my prior posts [1][2][3]
6. dbpedia (Wikipedia as a Data Web oriented Data Source)
7. And of course this blog post's permalink is a bona fide dereferencable URI.

And of course there is more to come such as Grandma's Semantic Web Browser which is coming from Zitgist LLC (pronounced: Zeitgeist) a joint venture of OpenLink Software and Frederick Giasson.