"The API has been arguably the most important [...] thing we've done with Twitter. It has allowed us, first of all, to keep the service very simple and create a simple API so that developers can build on top of our infrastructure and come up with ideas that are way better than our ideas, and build things like Twitterrific, which is just a beautiful elegant way to use Twitter that we wouldn't have been able to get to, being a very small team."
Biz Stone, co-founder of Twitter
This article provides a glossary of terms associated with open APIs which can serve as an introduction to the other articles in this issue of the OSBR. We then discuss the business opportunities that can be created through an open API and provide video and text resources which present further thoughts on the business value inherent in open APIs.
Glossary of Terms
Here we present definitions for the most commonly used terms associated with open APIs.
AJAX: asynchronous JavaScript and XML. Enables updates to a web page without requiring the browser to reload the page. The rationale behind AJAX is that often only a small portion of the web page changes. Web pages using AJAX are significantly more responsive than pages that do not.
API: application programming interface. Wikipedia defines an API as "a set of routines, data structures, object classes and/or protocols provided by libraries and/or operating system services in order to support the building of applications".
Collective intelligence: collective intelligence is the information and insights that can be extracted from the collective set of interactions and contributions made by a user community, and the use of this intelligence to act as a filter for what is valuable to the users. Collective intelligence emerges from user-contributed content and the process of sensemaking.
Generativity: the capacity of a system to produce unanticipated changes through unfiltered contributions from broad and varied audiences. Technological generativity describes the quality of the Internet that allows people unrelated to vendors to produce content in the form of applications through mashups and user-contributed content in the form of wikis and blogs. The first generation of the Internet was a non-generative system whose content was controlled by a small number of parties. With Web 2.0 technologies and practices, the generative potential of Web has reemerged, allowing users to participate and collaborate in the creation of its content.
Mashup: mashups combine data and services provided by third parties through open APIs, such as Google Maps and Flickr, as well as internal data sources owned by users. Mashups are an example of recombinant innovation. Mashups can be implemented directly within the client browser or on a server. Client-side mashups often access open APIs through AJAX. Wikipedia describes and provides examples of different types of mashups.
Network effect: network effects, also known as network externalities, occur when the value of a good, service or a shared resource is affected by the number of its users. Network effects can be positive when the value of the good increases with the number of users. An example of a positive network effect is seen when more people use a type of credit card, causing more merchants to accept it. Network effect can also be negative when the value decreases as the number of users increase. A highway, jammed with cars reduces its value to each commuter as traffic slows, is an example of a negative network effect.
Open API: an open API gives users access to the open content data or services of an information technology (IT) platform. A well-known example is the Google Maps API which generates maps for a given location, and its output can be combined with other data and services into mashups. Open APIs provide users with an innovation toolkit in the sense of the user innovation paradigm. The P2P Foundation provides a further discussion on the importance of open APIs.
Open content: one of the defining characteristics of Web 2.0 is openness. Open content is published in a format that explicitly allows copying and modification. The Creative Commons provides a choice of licenses which are often used to describe the rights associated with open content.
Recombinant innovation: describes a view of innovation as a process through which new ideas emerge as the combination of existing ideas. This process can shorten the learning curve as it combines known elements in novel ways. Recombinant innovation allows innovators to share past experience and provides a diversity of problem solving frames.
Sensemaking: the capacity for making sense of complex sets of information during a situation in which new problems, opportunities, or tasks present themselves, or old ones resurface. Sensemaking aims to help people act in an informed and effective manner. Mashups and other Web 2.0 technologies support the sensemaking process by enabling collaboration, visualization, and casual interaction with data sources through which users can gain insights into the structure and interpretation of the data.
User-contributed content: Web 2.0 practices and technologies have empowered users to participate and collaborate in the creation of content. This content created by users is the basis for the existence of social networking websites and portals. Similarly, websites like Flickr and YouTube primarily depend upon user uploaded content and provide a framework to categorize the content using user-generated tags. Contributions such as photos, reviews, ratings, and lists of friends are considered to be active. Contributions in the form of behavioural data such as clickstreams, page views, and purchases as well as resources such as computing capacity are considered to be passive.
User innovation: traditionally, product development has been company-centric. In this model, the interface to the customer is the product prototype and feedback on how well customer needs are being met is obtained late in the product development cycle. In user innovation, the locus of innovation shifts from the company to the customer. The new interface to the customer is now a solution platform that customers can adapt to their needs using innovation toolkits. Open APIs can be considered innovation toolkits.
Web 2.0: a phenomemon that forms the basis of the next generation of the Internet and that manifests itself in terms of user-contributed content, openness as seen in open APIs and open content, and network effects.
Web scraping: an approach to extract structured information from websites that do not offer an open API to provide data access. An API to a website created through web scraping is also known as an implicit API. An example of web scraping is HousingMaps, the first Google Maps mashup which mixed data from Craigslist with Google's maps. At the time, neither Craigslist or Google Maps provided an open API to their services, so the creator of HousingMaps had to resort to web scraping to extract the data from these sites.
Widgets: also known as gadgets, these are small, reusable components that allow content from multiple sources to be easily integrated into websites without programming. For example, a widget can provide access to a user's Twitter feeds on her home page. The term widget can be used to refer to a mashup that composes only one open API. Most early mashups were widgets, and widgets continue to represent a significant percentage of mashups. To integrate a widget into your website, you only need to paste an URL or a piece of JavaScript into the HTML code of your page.
Importance of Open APIs
As mentioned in the introductory quote by Twitter co-founder Biz Stone, opening an API to an application creates opportunities for external innovation. Giving third-party developers programmatic access to an application allows them to add value in unanticipated ways, and adds resources to your development effort that you would not otherwise have access to. You can thus tap into the long tail of underserved users who write their own applications to meet their specific needs, if given the opportunity. With external development, the risk of development is carried by others, but you can nonetheless reap the benefits from successful innovations. This is what Google does when it gives users access to its vast computing infrastructure when providing such services as Google Maps, or any of its other .
When you open an API, follow established standards where they exist. Jakob's law implies that the biggest opportunity to increase site traffic is to give users an easy way of integrating your content into their sites. This can take the form of a widget or an open API which other developers can use to build widgets and mashups that leverage your API. Increased traffic provides opportunities to monetize your application through other avenues, such as advertising. If your application or service collects information from users, such as photos or profiles, users expect to get access to their information through an open API. They don't want to be locked into a particular service, and will base their decision on which service to use, in part, on the existence of an open API.
The glossary definitions were contributed by the students of the SYSC 5801 course on Web 2.0: Collective Web, a graduate course taught in the TIM program. This glossary will be part of wiki book on Web 2.0 that the students have written collectively, implementing the very ideas underlying Web 2.0.