How to get started with RDF? (Particularly for relational database developers?)

Question

I am putting together a catalog (catalogs by nature are just metadata), and so rather than using a database, I am using an RDF store and SPARQL processor to compile the data. I am at the pattern-matching stage (the fun part). So, I get to come up with lots of patterns that are simple to define in SPARQL, and then provide that information to the people who use the catalog.

Ok, here's my question:

I have worked on a few projects using RDF, and it seems like getting started is the hardest part (at least for me), particularily if I have to start from scratch. So, I have started to put together a very basic starter kit for myself, but I wanted to see if there is anything else out there that might be better... something like the interactive command lines that many scripting languages offer, or like phpMyAdmin (but for triples).

I have seen:

• Some Web front ends, attached to endpoints such as OpenLink (an example is http://dbpedia.org/sparql), but the ones I have seen still require a lot of manual work (because they are intended for a general audience).

• There are tools like the Tabulator (http://dig.csail.mit.edu/2007/tab/), but their focus is more on combining and visualizing datasets rather than creating new datasets.

• A lot of work also goes into describing existing data in RDF.

• Some tools that are paid online services (I would prefer to install my own)

Does anyone know of a system to help get started creating an initial RDF store, and setting user preferences, etc., to get started with new projects that use RDF.

Gelderland

It looks like the Tabulator does have feature for adding new content... I don't think I was able to get the Firefox Extension working. It seems to be outdated. – Gelderland

Answer 1

I would strongly recommend downloading and installing Top Braid Composer

It has loads of stuff to make Semantic Web development easier and there is a free edition.

Flirtatious

If I want to load a set of prefixes (with standard but also custom graphs that I have created), does the application save the prefixes for me? So, I can reuse the prefixes at a later time? Also, note that I might want to have several sets of prefixes depending on the data set that I am building. So, the ability to easily switch the set of prefixes depending on the project would be important. – Gelderland

This is very close to what I was talking about. – Gelderland

Answer 2

You might want to have a look at the Sesame Windows Client (SWC) (disclaimer: I am one of its developers).

SWC is a graphical desktop app (in .Net) for connecting with a Sesame server (or any SPARQL endpoint), but it also offers options to just create a local triplestore on the fly (without the need for a server). IMHO it's a useful tool for "getting started with RDF".

Perron

If I want to load a set of prefixes (with standard but also custom graphs that I have created), does the application save the prefixes for me? So, I can reuse the prefixes at a later time? – Gelderland

yes. the app also allows you to save SPARQL queries so you can easily reuse them later. – Perron

Answer 3

I've given a couple of talks on this subject titled Everyday Tools for the Semantic Web Developer which cover a variety of useful tools some of which I developed and others from the open source community.

Filbert

If I want to load a set of prefixes (with standard but also custom graphs that I have created), where do I save the prefixes so I can reuse them at a later time? – Gelderland

Not sure what you mean with save/re-use of prefixes in your specific case or application but are you aware of prefix.cc ...? Where you can also get dumps of prefix - namespace mappings in JSON. – Longterm

So, prefixes are helpful for us humans :) ...computers really don't have a preference. Computers just process strings. Prefixes are used to shorten a URI into a prefix & local part. My own data could be identified by a unique URI like <my-data/ID>, and it could be part of a unique graph <my-graph>. If I have to post my graph and my data prefixes to prefix.cc, that seems like it's adding another layer of complexity. Wouldn't it help if a developer UI allows for custom prefixes to be defined locally? – Gelderland

Answer 4

You might want to have a look at the LOD2 stack we're developing. Further background on the phases (from modeling to publishing) can be found in the Linked Data Life Cycles.

Longterm

Why Debian? Doesn't that box your offering into a corner, when it's not necessary? – Gelderland

Answer 5

Graphity PHP version is an object-oriented framework that combines JAX-RS-style RESTful API with Jena-style RDF API, and is based solely on W3C standards. Disclaimer: I am one of the developers.

It's easiest to use with a remote RDF cloud-store like Dydra.

Leontina

Does it provide a frontend UI for browsing the RDF graphs? Or is it a programming library? I'm looking for the first one, not the second. – Gelderland

@BiagioArobba - the recent Java release includes a Linked Data browser which provides a generic UI over RDF: github.com/Graphity/graphity-browser – Scrapple