Introduction to Mobile Blogging

Overview of Blogging

Weblogging is a technique that makes it easy for people to publish their thoughts on the World Wide Web. Since the dawn of the Web, it's always been possible to publish content, but blogging simplifies the process and adds important features. Anyone with a web browser can publish a blog, without knowing HTML or any of the other technologies usually associated with web publishing: FTP, Telnet, Javascript, Java Servlets. Blogging is still in a volcanic stage technologically; the landscape is covered with competing and rapidly evolving packages and protocols.

The term "blog" is a shortened version of "weblog," which refers to a web site that is frequently updated, diary fashion. "Weblog" itself is based on "web," as in the World Wide Web, and "log", in the sense of a record of events.

Anton Zuiker has written an excellent, concise description of blogging.

From a user perspective, blogging is straightforward. The simplest way to create a blog of your own is to sign up for one of several blog services. Some of the free ones are Blogger, JRoller, Pitas, Blog-City, and 22 Blog.

Blogging Architecture

Blogging is supported by a web application, a blog server, that generates pages and allows authors to upload new blog entries. Blog servers vary in complexity, but all offer the same basic functionality:

• Authors can upload new blog entries. Most of the time, they enter blog updates into a form in a browser. I'll describe some of the other possibilities in this article.
• Readers can view a list of blog entries using a web browser. The blog server usually presents these in reverse chronological order, so that the newest entries are at the top of the blog page.

Advanced features have appeared:

• Some servers allow readers to post comments in response to blog entries. Each blog entry may thus be the root of a complete discussion between the blog's author and its readers.
• The server may automatically generate RSS feeds. An RSS file is an XML document that summarizes a site's content; some blog servers will create an RSS file based on the current blog entries.

Many blog servers are open source projects. Some examples:

• b2
• BigBlogTool
• Blosxom
• Drupal
• MovableType
• Nucleus
• Roller

Blog Server APIs

The most common client is an HTML form in a browser. This is a relatively simple solution because the update form can be easily packaged as part of the blog server application.

As blogging has grown in popularity, however, alternate blog clients have emerged. Alternate clients are possible only when the server publishes an application programming interface (API). Suppose I write a blog server. The only way other people can write blog clients is if I publish an API that clients can use to update a blog.

What's the only thing better than a published API? That's right, a standard published API. Probably the most widespread API is the Blogger 1.0 API, which was followed up in Febrary 2003 by the Blogger 2.0 API. Some of the other popular blog server APIs are MetaWeblog and LiveJournal.

Another standard currently in development is Atom, which is the goal of the Echo Project.

Diego Doval has written an interesting summary of the different APIs (as a blog, appropriately enough).

All the current blog server APIs are accessed via XML-RPC; basically, the client sends a request as an XML document, and the server responds with another XML document after it has performed some work. To add a blog entry, for example, the client sends an XML document that describes the entry. The server creates the entry in its database, and returns to the client an XML document reporting success.

Client Options
Once the server has a public API, anybody can write a client. Vari