Solid Amsterdam – 1st Session Summary

On October 10th a first Solid Amsterdam session was organized by Jeroen van Beele with support of Solid-Inrupt, Platform Linked Data Netherlands (PLDN), Triply and the VU Amsterdam. Since this was the 4th Solid event in the Netherlands our aim was also to go into more detail regarding the different Solid front end and back end development aspects and the Solid use cases we have worked on. 
In this session summary we will describe the highlights of this session and we will also give the links to the different presentations, apps and libraries that were presented during this session
==Meetup Intro==
Jeroen van Beele, the host of the Meetup, welcomed the 30 participants and introduced the first speaker Wouter Beek who works for Triply and the VU Amsterdam. One of the questions in Wouter’s presentation was: Can we re-host the LOD Cloud with high availability? Wouter showed us the standards and tooling that Triply works with and the services they can provide to their customers to make working with large amounts of Linked Data easier and more reliable also in relation to Solid. 
For more details, check the slides of his presentation.
==Solid Deep dive==
The second speaker, Michiel de Jong of Inrupt, highlighted why Solid is very important to all of us when we have our discussions about personal data management, data ownership and privacy. Solid gives us the means to free up personal data from apps and organizations that lock your data into their data silo’s by decoupling data from apps and by having the freedom of choice of which data provider(s) and apps you want to use and that you trust and where all your online personal data is stored in your Personal Operational Data Store (Pods) and can work with interoperable Solid apps. 
 
Two (or more) Solid apps, which offer the same or very similar functionality, are interoperable when a second Solid app can use the personal data that has been stored by a first Solid app and can add new personal data to that Pod, since it assumes and works with the same data shapes (e.g. two bookmark apps that use and add bookmark data in the same bookmarks.ttl in a Pod). This means that you can switch between interoperable Solid apps without losing any personal data. You have total freedom of choice in chosing a Pod provider and using Solid apps. Michiel also showed us in his presentation the different topics that are part of the Solid spec with the exception of CORS. This was mentioned during his presentation. Therefore we have also included a link to a Solid documentation page that decribes CORS in more detail. 
For more details, please check the of his presentation and the additional information about CORS on the web-access-control-spec page.
Then Vincent Tunru of Inrupt showed us, during a live demo, three possible client libraries you can use in combination with web apps to make it possible for the web apps to work with the Linked Data that is available in Pods. 
* rdflib
* LDflex
* Tripledoc
The emphasis for working with these libraries is not on Linked Data itself, but on how to make it as easy as possible for web developers and Pod users to work with the (linked) data that is available in Pods with e.g. LDflex and Tripledoc (while still having the benefits of Linked Data). Vincent showed us during a live demo, how e.g. read and write statements to Pods are implemented in a web app and also what the characteristics of each library are that developers can make a founded decision in which situation to use which library. 
For more details, check the of his presentation. And you can also check the Exploration of client-side RDF libraries on GitHub when you would like to experiment with these libraries. 
Vincent also highlighted the This Week in Solid updates for those that would to get regular updates on the latest Solid activities and developments.
==Solid Use cases==
During the second part of the Meetup we wanted to highlight some of the Solid Use cases we have been working on in the Netherlands. 
First Özcan Seker, a student from Saxxion, showed us the Social Linked Beer app he has been working on since September as part of an internship at the Dutch Cadastre, Land Registry and Mapping Agency (in short the Kadaster) till February next year. The app allows you to login as a brewery or as a beer drinker (two different use cases) and shows your Solid profile data within the app (with the date you started using this app, the number of check-ins and reviews you have created and your beer bonus points), how beer drinkers can make friends and create groups in that app and how they can check-in and write beer reviews. 
And onces we have added our Linked Beer and Brewery data we have available from dBeerPedia, we can add the functionality that beer drinkers can write more reviews for beers and share those reviews within the friends they have in groups. General aim for this use case is to get a better understanding of how Solid works with an easy to understand example and how we can apply our first Solid development best practices to other Solid use cases and to personal data management with Solid Pods in general.
The Social Linked Beer app and its source code can be found via:
* https://ozcanseker.github.io/Social-linked-beer/ (web app)
* https://github.com/ozcanseker/Social-linked-beer (source code)
Then Thom van Kalkeren of Ontolo.io showed us the different libraries they have been working on, which will make it e.g. easier to develop React apps that can make use of Linked Data (not only for developing Solid apps, but more in general for all kinds of Linked Data apps). Thom showed us for which projects they have used link-lib and how it works in more detail for developing Linked Data and Solid apps. 
Unfortunately we did not have enough time to go into all the details of the libraries they have developed, but the presentation gives a good overview of what they have worked on, what their future plans are and it also includes the links to all the resources of the different libraries on GitHub! We will check with Ontolo.io if they are interested to explain their libraries in more detail during a PLDN Conceptual Friday we can organize at our BDVC location in Utrecht.
* (slides)
And finally, Enno Meijers of Netwerk Digitaal Erfgoed (NDE) showed us the what Solid use case they have worked on together with Solid and Linked Data experts from IDLab. 
Together they have created a model to make Heritage data better discoverable via a central search index that works with data summaries of Heritage collections. Via these summaries you can get a first overview of which Heritage collections contain the term (or terms) you are looking for and from that first overview you can make a final selection for the collections that you would like to include in the query to request the desired data out of the Heritage collections. So, you can decide to query only a subset of the collections from that first overview to get exactly the data you are looking for and to make querying data more efficient. For more information on this case check:
* Zoeken in gedistribueerde erfgoedinformatie (web page)
Enno also referred to HackaLOD 2019, a hackathon that is organized every year at a very inspiring location. This year it will be organized at Radio Kootwijk (close to Apeldoorn). 
PLDN would like to participate in HackaLOD 2019 with a Solid development team and we we still have room for new team members. So, when you are interested in Solid and have web development experience (and preferably with Solid libraries), please contact us via: platformlinkeddatanl@gmail.com.
==Meetup Next steps==
During this first Solid Amsterdam session, we agreed upon a very essential element for the success of Solid and our digital future: Governance. And we would like to make this topic to be one of the key focal points for future Solid and Linked Data related activities. A first opportunity to do this, is during a symposium organized by Enno Meijers on Friday November 29th.
Symposium Publieke Infrastructuur
Date: Friday, November 29th, 2019
Time: 13:00 - 16:00 
Location: Theaterloods at Radio Kootwijk
And we will organize a 2nd Solid Amsterdam session:
Date: Thursday, January 30th, 2020
Time: 14:00 - 17:00
Location: VU Amsterdam/ HG-07A16 (38 / 19T)
Registration: Registration form
And some of the subjects of this session will be:
* Governance around Solid
* Business and revenue models around Solid
* Progress of Social Linked Beer app
* ...
In the weeks ahead we are working on the final program, suggestions are welcome.