Google Data client libraries are available to help you write client applications that use the Blogger Data API

http://code.google.com/apis/blogger/code.html


For each language, the client library provides tools and an abstraction layer, letting you construct queries and use response data without having to create HTTP requests or process HTTP responses by hand. Each client library provides classes that correspond to the elements and data types that the API uses. Each client library also provides extensions for specific Google services that have Data APIs.

• Blogged Upon sample to comment about external posts using the client library
  
• "Blog This" embedded blog editor using the client library
  http://gdata-javascript-client.googlecode.com/svn/trunk/samples/blogger/blog_this/blog_this.html
  When you click the Login button below, you are taken to Google's AuthSub page to authorize this page to access your Blogger feeds. Once you give permissions to this page, the login button will be replaced with a text area for creating a new blog entry. The editor reads a list of your blogs using the Blogger JavaScript client library, and posts to the desired blog.
  
• CalendBlogger Google Calendar to Blogger publisher using the client library
• blog.gears offline client for Blogger using Google Gears and the client library
• blog.press Blogger client using the client library

JavaScript client library

The JavaScript client library provides full read/write capabilities from within JavaScript. Read-only access is also available via raw JSON.

• Blogger interactive Developer's Guide for JavaScript
• Reference Guide (JSdoc)