I'm a MediaWiki developer, entrepreneur and author. I founded and run the MediaWiki consulting company WikiWorks and the MediaWiki-based wiki farm Referata. I also wrote the reference book Working with MediaWiki.
I can be contacted at any time at firstname.lastname@example.org.
My extensions 
Extensions I've created:
Semantic Forms · Semantic Drilldown ·Semantic Calendar (obsolete) ·Semantic Compound Queries · Wiki Garden (unreleased) · Data Transfer · Replace Text · External Data · Admin Links · Semantic Internal Objects · TemplateInfo · Approved Revs · HTML Tags
Extensions I've made substantial additions to:
Extensions I've made small contributions to:
Extensions I've otherwise helped to design:
Extension packages I've (co-)created:
An overview of my MediaWiki-development career 
Sometime in early 2006, I had the idea of creating a site like Rotten Tomatoes, but for political opinions - why was it so hard, I thought, to find the opinions of commentators on the important issues, when it was so easy to find aggregated opinions on any old movie, video game, consumer product etc.? The idea lay dormant for a while, but in June I suggested working on it to a friend of mine, Nick Grandy. The timing was good, since we were both between jobs (I had quit my last job the previous year, to work on a website that ended up not going anywhere, but that's a different story.) We both were fascinated by Wikipedia, and decided to set up the site as a wiki; given the controversial nature of political opinion, we thought that it was important to allow many users to edit it, to avoid charges of bias (or actual bias, for that matter). We also thought making it a wiki, and thus editable by everyone, would mean less work for us in the long run; an ironic thought, in retrospect.
We looked at a few solutions, and quickly settled on MediaWiki and the Semantic MediaWiki extension. From there, many decisions flowed: authors, sources (newspapers, magazines and the like), topics etc. would each be represented as a class, and each one would aggregate information so that a user could view opinions for each of these; and semantic information would be contained only within templates, enforcing structure throughout the site and making editing easier. In July, Nick also came up with the eventual name: "Discourse DB" (the site is still running, and you can see it here). We spent part of the summer in wi-fi cafes, creating the site. Part of that task involved making changes and additions to Semantic MediaWiki to enable our interface to look the way we wanted; that was my introduction to MediaWiki programming. In August I took a trip to Boston to attend Wikimania 2006, where I saw a few talks by Markus Krötzsch and Denny Vrandečić, the developers of Semantic MediaWiki; it was fortuitous timing, since Nick and I had some uncertainties about how the wiki should be designed, and I got to ask them directly; sadly, neither of them later remembered meeting me at that conference. In September the site was released.
For all the work we had done to make Discourse DB user-friendly, there was a problem with it, which was that it required users to enter Wikipedia-style template calls into pages to add information, a requirement that, as I discovered from talking to people, essentially made data entry impossible for the vast majority of potential users. In December I added a form on the site that prompted the user for the fields of an opinion item, turned those values into a template call and saved it to the wiki. Not a big deal, but it still took over a week of development time, mostly because the form had autocompletion of author and source names. It did make the entry of data much easier, though.
After the form was added, I had the thought that such a form-based semantic wiki site could eventually become extremely popular, since it allowed for widespread collaboration on data with an ease that had never been available before: you have the flexibility of a wiki combined with the power of a true database. Thinking about it more in January, that optimistic vision turned into a depressing one, as I imagined one programmer and/or administrator after another having the same idea, then spending the months that it had taken me and Nick to create such a site and its forms, and making all the same mistakes, or perhaps entirely different ones, all to create what were essentially copies of the same code. Soon afterwards, while sitting in a development meeting on an unrelated topic, I had a vision of being able to automate the creation of forms; this idea eventually became the Semantic Forms extension. The initial conception looked almost nothing like what the current solution does: it was going to be a component of Semantic MediaWiki and not a separate extension; it would generate complete, autonomous PHP code for each form on one's site, instead of using scripted form-definition files; and the forms would be used only for adding data - editing data would still have to be done by hand.
I worked on the code on and off over the next four months, and discussed it with a few of the SMW developers and others, and in May 2007 Semantic Forms 0.1 was released. I've since put a great deal of work into improving it and trying to make it a truly enterprise-level application, trying to reduce the amount of time needed to create a full structured semantic wiki from several months to several hours. A large number of developers and users have also helped, making invaluable code contributions, bug fixes and suggestions.
In June, at the encouragement of Sergey Chernyshev, a fellow SMW enthusiast (and early SF adopter), I created a Google Groups mailing list for Semantic Forms, which started off with around 10 members.
Starting in July I gave some feedback to Matt Williamson, an SF user who wanted to create a mapping tool, whose work would be released in September as the excellent Semantic Layers.
In August I also took on my first consulting job implementing an SMW- and SF-based semantic wiki (at my suggestion - they needed convincing); the experience proved very helpful in seeing the software through fresh eyes, and seeing what features are really needed by real-world users. This led to a set of changes in SF, as well as code I wrote to enable an XML export of the data, which that project required.
In November 2007 I had the thought that search by semantic properties could benefit from the same automation, and user-friendliness, that Semantic Forms attempts to do for data entry. I did some planning work on it, soliciting some feedback from the Semantic Forms users, and the next month I created and released the Semantic Drilldown extension.
In January 2008 the site Chickipedia was launched - I wasn't involved with it, but I mention it because it was, and perhaps remains, the biggest and most high-profile user of Semantic Forms. That same month, I was commissioned to create a calendar extension; Semantic Calendar was released in February. Just as with my previous extensions, the semantic nature of the data made it very easy to create a generic, all-purpose application; much easier than if the application were querying a typical relational database.
Later in February I packaged the XML-export code I created before, releasing it as the extension Data Transfer.
By March, I was working almost exclusively on MediaWiki-related projects in one way or another. I was hired to set up some semantic wikis, and do development work for a (non-semantic) wiki-based company. I was also commissioned to upgrade Semantic Drilldown, an upgrade that was released in April as SD 0.4. When I needed to make new business cards, I had them read "MediaWiki developer" as my job title.
In April I released the extension Replace Text, which does global text replacements, and whose main purpose was to get around SMW's limitation of semantic properties not following redirects. As with Data Transfer, I had already created most of the code well beforehand, for internal use on various projects, but hadn't gotten around to releasing it until later.
In July I released the site Referata, a site that hosts wikis that use SMW and these other extensions. This site had been in the works for a long time, in fact nearly as long as Semantic Forms had been out; but its scope kept expanding as other extensions were added. That same month I also took over the development of the Semantic Google Maps extension, which had lain neglected for a while and lacked the ability to do aggregation of points. I added this ability in and released a new version. The next week, I flew to Alexandria, Egypt for Wikimania 2008, where I gave a talk on my various extensions and co-presented with Markus and Denny; it was the first time I had seen either one since Wikimania 2006, and we had some very interesting conversations; it was a nice trip all around. After getting back from Egypt, I created and released the Semantic MediaWiki Community Wiki, a wiki on Referata intended to serve as a directory for the people, sites and other information connected with SMW. It was a rewarding experience being able to create the site, announce it and start getting the first contributions all within a matter of hours.
In August I was invited to visit the RPI Tetherless World Constellation, a research group headed by semantic-web pioneer James Hendler; it turned out that they were doing some rather extensive work around Semantic MediaWiki, including several of my extensions. It was very interesting to see the extensions being used in a research context, and some of the demos were quite thought-provoking, including the RPI Map, which displays multiple sets of points on the same map. Later in August I released the Semantic MediaWiki quick reference guide (available in PNG and PDF formats), a one-page "cheat sheet" for the SMW, Semantic Forms, Semantic Drilldown and Semantic Calendar extensions. The idea for it had actually come in June, though the execution took a little time.
In September the wiki Verwaltungskooperation, run by the Austrian KDZ - Centre for Public Administration Research, which uses a number of my extensions including Semantic Forms, Semantic Drilldown and Semantic Google Maps, won a jury award in Austria's Multimedia State Awards. It was, I believe, the first time my software or any wiki running it received public recognition.
In November I released the extension Semantic Compound Queries, which allows for calling multiple queries at the same time; it was directly inspired by the RPI Map I saw three months earlier. Later that month, we held the first-ever Semantic MediaWiki users meeting in Cambridge, Massachusetts, which I had helped to organize; the meeting was a success, with around 30 attendees, and a lot of focused discussions on both the business and technical side of things.
In December I deprecated Semantic Calendar, making it my first obsolete extension. Later that month I added four new formats to Semantic Result Formats: 'sum', 'average', 'min' and 'max', all simple math functions. I also made some changes to the setup of SRF, which made me, at least temporarily, in charge of that extension as well. I also released a new version of the quick reference guide, incorporating these and other changes.
In January 2009 I released the External Data extension, which doesn't require Semantic MediaWiki, but which was created in order to allow SMW to use data from external APIs.
In February, another developer added code to enable caching in External Data; later, in June, yet another developer would contribute code that allowed External Data to access data directly from both databases and LDAP servers. I still consider External Data my ultimate "stone soup" project, whose initial version contained the seed of a good idea that others saw the potential in, and turned into a full-featured extension.
In March a wiki I helped develop, the OpenCongress wiki, launched; it was the first high-profile usage of the External Data extension, along with being one of the most high-profile usages of Semantic MediaWiki. I believe it also provided a template (no pun intended) for how a MediaWiki wiki can be used for data integration: the site, through External Data and some other extensions, displayed data from outside APIs, maps and feeds, in (hopefully) seamless conjunction with homegrown data compiled using Semantic Forms.
In April I added the importing of XML to the Data Transfer extension, which finally justified its name (it was always intended for both import and export).
May was a busy month: I released the extension Admin Links, which creates a special page meant to serve as a "control panel" for the wiki; until then, MediaWiki had not really had such a feature. It was actually based on a "helpful links" page I had created before for Referata. I also helped bring about the SMW testimonials page, which was intended to help bring SMW in line with other enterprise applications, in order to help "sell" it to businesses. I also added the 'outline' format to Semantic Result Formats. I also added import of CSV files to Data Transfer, which proved much more useful than import of XML files (I'm still not sure if XML-import is useful at all.) Later that month I added support for Semantic MediaWiki and four of its related extensions to the great Configure extension, so that their settings could now be configured through the wiki interface.
In May I also started supervising Jeroen De Dauw, a student in the Google Summer of Code, whose project was to create a "Semantic Maps" extension that would integrate Semantic Google Maps, Semantic Layers and hopefully some other mapping services.
In June, Sergey Chernyshev and I released the Semantic Bundle - a package of Semantic MediaWiki and 14 other extensions that are often used in conjunction with it. The aim was to try to simplify the process of installing SMW for new users, given the large tangle of extensions that had grown around it (which, admittedly, both Sergey and I had helped a good deal to create).
In July, I helped Jeroen with the first release from the Google Summer of Code project, which had by now become two extensions: Maps and Semantic Maps. These two extensions helped to provide a rather-complete mapping solution for Semantic MediaWiki, by providing full support for Google Maps, Google Earth, OpenLayers (previously the basis of Semantic Layers), and Yahoo! Maps. That led quickly to the deprecation of the Semantic Google Maps and Semantic Layers extensions. I also terminated the SF mailing list (now at 250 members) that month; all future emails were to be sent to the SMW mailing lists, which was part of an attempt to streamline the communication process. That month I also attended the 2009 New York City Wiki-Conference, where I presented about both the new maps extensions and Semantic MediaWiki in general.
In August I released the extension Semantic Internal Objects, which lets you store so-called "n-ary relations" in SMW in a flexible way; this was something that had been discussed for over two years at that point. Later that month was the Wikimania conference in Buenos Aires, where I presented about the External Data extension, as well as being on a panel about Semantic MediaWiki. This was also the Wikimania where SMW and various of the other spinoff extensions (some of them mine) began to be seriously discussed as additions onto Wikipedia.
In September I joined the Wikipedia Usability Initiative as a part-time consultant, working to create a system that could aid in the editing of template calls; the project was separate from Semantic Forms, but it was based in part on my experiences with Semantic Forms. I also released an upgraded version of the SMW Quick Reference, now at two pages and covering ten extensions.
In October I met with the Usability Initiative people again, and we fleshed out the details of the template-form-editing project.
In November I released the TemplateInfo extension, which was the first part of the work toward getting template forms on Wikipedia. I also launched, with the help of some others, WikiWorks, a MediaWiki consulting company with a focus on Semantic MediaWiki, and my attempt to turn the consulting I had been doing into a full-fledged business. We also held the first-ever SMW Camp, a direct extension of the SMW Users Meeting held a year earlier. This one happened in Karlsruhe, Germany, and was hosted by ontoprise. It was another successful event, with over 40 attendees, and two days of in-depth discussions and presentations. There, I finally got to meet Jeroen and some other SMW developers that I had only talked with via the internet.
In December I flew to Shanghai to present about Semantic MediaWiki at both the Asian Semantic Web Conference and at Fudan University. Interestingly, two of the other talks at the conference were about projects that used SMW and Semantic Forms, which to me was an indicator of the software's growing importance in the academic world.
In January 2010 WikiWorks started working on our first consulting projects, which was a great development. I also created the first version of the Semantic MediaWiki FAQ.
In March I entered the ohloh list of top 10 MediaWiki contributors for the first time (the count includes contributions to extensions, not just core MediaWiki code). I also helped Rowan Rodrik van der Molen merge his Semantic Gallery extension into the Semantic Result Formats extension.
In June I released a new extension, Approved Revs, that was meant to be a much simpler version of the FlaggedRevs extension. It was inspired by conversations I had had with several people about the need for more workflow in MediaWiki and SMW, along with a failed attempt before to install FlaggedRevs. I also attended Recent Changes Camp, in Montreal - it was nice to hear about the experiences of developers of other wiki applications, which I hadn't heard much of until then.
In July I was briefly quoted in an online article in Technology Review about adding semantic meaning to Wikipedia.
In September, I attended the second SMWCon, in Amsterdam, which had a little over 40 attendees. On a professional level, I thought this conference was notable for two things: the seriousness of the talks (many of the talks covered the usage of SMW for pretty major applications), and the fact that it served as the beginnings of what looked like a serious project to integrate the semantic-web technologies of RDF and SPARQL much more directly into SMW.
In October, I helped with the design and launch of a new look for the semantic-mediawiki.org homepage. (The logo for SMW also changed in that month, but I wasn't involved with that one.) Later that month I attended the GOSCON conference, which was notable mostly because I got to meet Ward Cunningham who invented wikis, and gave them their name; he gave the closing keynote. He's basically out of the wiki world by now, but it was great to meet him, and nice to hear his thoughts about technology, and to tell him a little about what I do.
November saw the launch of the SMW wiki of the month feature on the website, a project I helped create and basically ran by myself until August 2011, when it was taken over by others.
In December, WikiWorks was commissioned by Texas Instruments (still our biggest client) to create our first two full-fledged extensions: the Push and Live Translate extensions. Both were written (and named) by Jeroen, with some supervision from me. That same month, I was interviewed as part of the ontoprise "Semantic Minds" series, of people involved with SMW.
In February 2011 I flew to California to attend the "Wikimedia Data Summit", where various discussions happened about making better use of the data accumulated on Wikimedia - I was there to present about, and somewhat make the case for, Semantic MediaWiki. There were no real conclusions to the meeting, but it was a good official start to the project to add semantic capabilities to Wikipedia (which would the next year become the Wikidata project).
That month, Stephan Gambke became an official co-author of Semantic Forms, after having made a number of crucial contributions to the code. It was an important step, because it indicated that Semantic Forms (still by far my most important MediaWiki contribution) could theoretically live on beyond my direct involvement in it.
In March the Open Semantic Data Association was founded, and I was named its vice president (Markus was named president). OSDA is the non-profit organization that is meant to provide some financial support and stability to the Semantic MediaWiki project. It was later officially registered in August.
In April I attended the Spring 2011 SMWCon in Arlington, Virginia, an event I had helped to organize. It was our first three-day conference - the first day was a full day of paid tutorials. The tutorial day turned out great, with around 25 attendees, and essentially paid for the rest of the conference. The conference itself was also a success.
In May I started mentoring Ankit Garg, a student in the Google Summer of Code, in a project to create the extension Page Schemas, an attempt to create a framework for defining data structures. It was the third year in a row in which was a mentor for a Wikimedia Foundation GSoC project.
In June I helped the people at the site WikiIndex install Semantic MediaWiki. It was cool because it enabled probably the first-ever statistical breakdown of the popularity of different wiki engines on public wikis.
In August I attended my fourth Wikimania, in Haifa, Israel. It was a great conference, and a great excuse to visit Israel, where I had grown up, and specifically my old hometown of Haifa. As usual, I was part of a presentation about Semantic MediaWiki, this one with (promisingly) a greater focus on its potential use on Wikipedia. August also saw a successful end to the Google Summer of Code, and the official release of the Page Schemas extension.
In September I overhauled the Semantic Forms documentation, to make it easier to use. Later that month I traveled to Berlin to attend the Fall 2011 SMWCon, which was another great event. This one was notable in that about half the talks related to RDF or the Semantic Web in some way, including many real-life use cases. It showed a clear trend of SMW becoming more of a standard Semantic Web tool. And on my way back home I visited London, to give a seminar about SMW to another group of very Semantic-Web-savvy people.
In November I helped move over Referata to a new, faster server, as a result of some increasingly frequent system crashes on the old server. It was an unexpectedly painful process, but it did result in markedly better performance for the site once everything was in place.
In January we got stickers made for WikiWorks... it doesn't sound like a big deal, but it was my first-ever "swag".
In February I released a new version of Semantic Forms, 2.4, that contained the new parameter "values dependendent on=", which lets the autocompletion values for one form field be based on the current value of another one. It was a feature that people had requested for a long time, and it was notable in that that kind of dependent autocompletion had been available in that very first form I created, for Discourse DB - so now finally, after more than five years, Semantic Forms was able to reproduce in its entirety the form that had inspired it.
In April I attended (and served as the program chair for) SMWCon Spring 2012, held in Carlsbad, California. It was our first true West Coast event, and it showed that there was a surprisingly high (to me) level of interest in the software in California. It was definitely another successful event.
In June all of my extensions moved from SVN to Git, in conjunction with the rest of the MediaWiki code, and I learned, or at least started to learn, the workings of Wikimedia's new Git/Gerrit system.
In July I took the bus to attend Wikimania in Washington, D.C. There were at least three talks by users of SMW, talking about their SMW-based wikis, which was great to see. And it was neat to hear about all the technical initiatives coming out of the Wikimedia Foundation, including VisualEditor, Flow and of course Wikidata.
In September I added a hook into core MediaWiki, for use by the Approved Revs extension. I had previously added a hook into MediaWiki during the SVN days, but it had been removed a few months later as part of rewrite. So I was pleased to once again be, though to the smallest extent possible, a core MediaWiki developer.
In November OSDA got its own domain, and a snazzy new logo. That month I also helped oversee the release of version 0.2 of Semantic Watchlist. This was an extension that had been created the previous year as a WikiWorks project, but that I hadn't been involved with directly. As part of the new version, I helped to re-design the admin interface.
Later in November, I released Working with MediaWiki, a MediaWiki reference book. It's my first-ever book, and was the culmination of over a year of effort.
In February I made some important fixes to the Widgets extension, so that it once again worked fully after having been transferred to Git the year before.
In March I helped organize and run SMWCon Spring 2013, which took place in my hometown of New York City. It was a great conference, with a remarkable diversity of interesting projects being presented, though I had to spend the next few days basically just recuperating.
In April I started work on the MediaWiki data browser project, a six-month project that I got an Individual Engagement Grant from the Wikimedia Foundation to work on. I viewed at as a next step in the concept of generic data applications, which Semantic MediaWiki is a very important part of.
And that's the story, until now, of my MediaWiki career. You can read more about me at my homepage, at http://yaronkoren.com.