Some of the things that need to be considered in writing an API may be classified as the characteristics of a good API. These characteristics include:
- Easy to comprehend
- Ease of use
- Almost impossible to misuse
- Easy maintenance of code
- Satisfies the requirements
- Can be easily extended
- Appropriate to the target user

Blogs is the latest craze nowadays. The adults are the usual users but even kids are getting hooked as well. A blog can be best described as a online journal or diary that is available on the world wide web. The activity of editing and posting articles in the blog is “blogging” and someone who writes a blog is called a blogger.
It is usually updated everyday using a program that enables people with no formal IT background to edit and maintain a blog. Postings are usually arranged chronologically with the most recent articles featured first for everyone to read.

This separation is what exactly implies the rules for designing and maintaining an API. If the product was developed by a tight team, building it at once, there would be no need to interface since it is definitely going to work. In the practical world, things are not done this way. Products are produced from completely independent projects and developed by different teams not necessarily aware of the other’s existence. Projects are built independently but the need to communicate is still there. Hence the need for a stable link that can be used for such communication.

The system is fitted with function keys that act as Learn and Reset which helps to secure the system from unauthorized access. The function of the Learn key is to input the master barcode while the Reset key prevents the operator from restarting the system which can result in fatal execution errors.

Below are twitter status codes:
• 200 OK: means OK no error.
• 304 Not Modified: data doesn’t modified.
• 400 Bad Request: returns your request as invalid.
• 401 Not Authorized: credentials supplied are not legitimate or provide authentication credentials,
• 403 Forbidden: Requests are refusing to fulfill it by the system it will be followed by explanation why.
• 404 Not found: either it is no such user exists or an invalid URI.
• 500 Internal Server Error: something wrong. Post at twitter group and it will help you.
• 502 Bad Gateway: an message you’ve got if Twitter is down or being upgraded.
• 503 Service Unavailable: You’ll get message Try Again Later. Servers are running, but requests are too many

• List Media sends back the available media, currently news, videos, and images.
• List Containers sends back the catalog of accessible topic containers, e.g. “Technology,” “World & Business,” and so on, and the topics within each container. List Topics is still there and still returns the topics directly.
• List Stories sends back a blended view of all media: news, videos, and images.
• List Stories so you can demand for list of stories of a single medium (e.g. only news), or request a subset of media (e.g. news and videos, but not images).
• List Stories now features a thumbnail element for stories that have a thumbnail available. Thumbnails are in different size.

Wiki is a piece of server software that enables web users to freely edit the Web page content using any Web browser like firefoz or safari or IE. It tends to support hyperlinks and has a simple text syntax for modifying new webpages and cross-links between internal pages. The most notable example of a public wiki is Wikipedia. It is an online and free encyclopedia where everyone and anyone can contribute to a subject area. Wikis relies heaviy on user input and cooperation. They do this by providing a mechanism for users to give their input on any topic and are increasing productivity for organizations and various companies around the globe. Its simple, easy to maintain and highly flexible, and fits perfectly to today’s business needs.

For us to fully understand the present, sometimes we need to go back in time. Here’s a short timeline on how web services like API’s came to be. They basicall allow business proprietors to receive comments and suggestions from their clients and users which isn’t reall ythat much different from other sites on the net.
I must admit that the title relatively aims to give you a simple idea about API’s. You’ve experienced these mechanisms all over the web and i bet you’ve used them as well. A few of the more renowned examples include forums, wikis, and blogs. There are more examples that are less obvious but these top 3 fits perfectly with the description.

You must have heard of Picasa, the photo organizer that makes it easy to locate your photos, do simple edits and effects, and share them online. Picasa has two APIs that programmers can work with:

Picasa Web Uploader API lets you upload photos from Picasa to email and blog, preview photos before sending. The API gives developers the flexibility to set the image sizes and also allows video uploads.

Picasa Button API lets developers add a custom button to the Picasa UI and customize so that end users will be able to export Picasa images to other applications. Each button has four elements: an optional icon, label, tooltip and verb.

Most individuals have a number of public profiles and blogs. But it can be tedious to make all the connections with all your contacts from one site to another. Enter the Social Graph API, which shows public connections between people. Programmers can use this data to come up with an “add friends” functionality. Publicly available information and relationships from indexed webpages are used for this API. The Google crawler looks for links indicating that a profile is a “friend” or “me”. Open standards like XFN (XHTML Friends Network) and FOAF (Friend Of A Friend) are used to show relationships. Test drive the example apps such as Site Connectivity, My Connections and Parameter Playground.