In my efforts to write about so-called open technologies I have already brought you an Open Source 101. Today I want to talk about the Open Graph Protocol.
The Open Graph Protocol, or OGP, as it is abbreviated, was designed by Facebook and is used for the Like-Buttons, but every other service can consume and use this meta data as well. It is used to add very simple meta data to websites and is based on RDFa, which is very interesting in itself, but I don’t want to go into detail right here. The basic data added is url, title, image and type. One could argue that title and url is already a part of a web page, but OGP allows to enter canonical values, for example if there are multiple URLs pointing to the same page. The image is used as a visual representation, similar to a Favicon, but larger.
The type is where things get interesting, because a web page can be a description of a person, a thing or a place that exists in the real world, such as an actor, a movie or a cinema. Facebook assumes that if I click a Like-button on this kind of page, I’m not really liking the page, I’m liking the object that it represents (such as the movie). For these real world objects, there’s some additional meta data that can be specified, such as the physical location.
I’ve added OGP markup to my blog. If you also have a blog hosted on Tumblr like this, I’ve prepared a gist of code which you can simply add to your template between <head> and </head>, and it will enter the appropriate data for every article you write:
Open source is a big thing nowadays and it’s maybe the first term to make “open” a buzzword in technology. Thus, for the series on this term which I had promised you, I thought of starting with open source.
Let’s begin with some basics: Software is generally written in a high-level programming language and then transformed into low-level machine code by a compiler. The first language (the “source code”) is the one understood by developers and the second language (the “binary”) is the one understood by computers. If you install software on your computer, it comes in its binary form, e.g. an .exe file on Windows, which is sufficient to use it.
Now, if a software is open source, it means that every user can also get access to the source code. While most users won’t care about the sources and just want to use the software, developers and other geeks will be happy about being able to look into the inside of how their favorite software works and also being able to modify it and compile their own version of the binary.
Open source software is usually published free of charge, which is one of the obvious advantages, especially for private consumers who don’t like to spend money on software. For these consumers, open source equals freeware, but those terms shouldn’t be confused. To make things even more confusing, there’s also the term “free software” which is also open source, but freeware is not always free software.
Open source advocates generally point out that “free of charge” isn’t the only advantage of open source software. Rather, the focus is on freedom. A software offered as binary is a “take it or leave it” offer, but open source allows the modification of a product to make it adapt better to the requirement. For corporations, this can be even more important than price.
Some open source software is released in the so-called public domain, which means that the author decided to give up the copyright on their work. For the user it means they can do whatever they want with such software. Most open source software, however, is published under a specific license, which may restrict or ensure the freedom associated with the software. This is important because software developers generally build a project by combining existing code modules (libraries, frameworks etc.) written by other developers and extend it with their own code. Typical licenses define the terms under which open source code may be integrated into a new project:
I think this is as far as I can go in a basic introduction to open source, even though this topic could be dealt with in any level of detail. Some people use open source in a pragmatic way while others treat it almost like a religion; that alone could fill many posts. I’m a pragmatic user of open source software and seeing how many great open source projects have been created, it is really interesting to think about the impact on the industry. As open source is generally distributed free of charge, there’s the question of viable business models for companies in the field of software development. Cloud computing and Software-as-a-service as well as the advent of scripting languages who don’t use a traditional compiler have an impact on open source as well. Another interesting question is the motivation of developers to release their work as open source. I’ll be writing more on these topics soon, so stay tuned!
On 18th July, there was the Federated Social Web Summit taking place in Portland. This was an invite-only event for tech geeks involved in a lot of open technologies that I still owe you to explain. While I haven’t been there, I would like to link the coverage of this event on the blogs for you to read, if you are as curious as myself about it:
Did I miss anything interesting?!
Open is the opposite of close, what else?! Well, it’s not that easy. The technology crowd and web advocates have come up with a whole bunch of buzzwords. Open Source, Open Content, Open Data, Open Standards, Open Protocols, OpenID, Open Cloud, the Open Web … are you still following? Companies are bragging how open they are. Opening up, that means being transparent, allowing outsiders to look into things that are usually hidden from them. While non-profits and grassroots movements may develop so-called open technology for the good of everyone, companies will certainly look into how they really profit from opening up. Working with technologies and products that use the “open” label every day, I thought I should start a small series on this blog to solve the buzzword bingo and deal with potential misconceptions. So stay tuned.
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