Blueprint is Yahoo's platform for building mobile sites and platforms. The platform facilitates creation of device-independent mobile applications. Similar to Java, a runtime environment is installed on the device, allowing developers to design apps without worrying about screen resolution, device features such as GPS, and other common mobile development issues.
Using Blueprint, developers can deliver content in three ways:
1. Mobile Widgets under Yahoo! Go, Yahoo's app browser application where users can subscribe to apps like Apple's app store
2. Mobile sites available via any standard web browser (Note: some important features such as GPS are not available using this method)
3. Mobile apps that are configured to run specifically on a standalone version of the Blueprint runtime
All applications use an XML markup set called Blueprint (loosely based on XForms). The markup is served up through Yahoo's Blueprint servers to the individual devices (in the case of 1 or 2 above). The great thing about the XML markup is that your server-side code can be developed in any language. Yahoo provides documentation and files on using PHP to generate the XML, but I have found other sites that have .NET classes for automatically generating the XML elements as well. Of course, for static data, you can always just create an XML file with the proper elements and serve this up. Our site was delivered via method #2 above simply because it was the most efficient for debugging.
All in all, the technology is very straightforward to learn. My team at Startup Weekend was able to start from scratch with this technology and have a functional investment property search application in a few days. The most difficult portion is understanding the flow of information from the device to a web server to yahoo, etc. Yahoo provides some great documentation at http://mobile.yahoo.com/developers.
Here's a diagram explaining the flow of information from device, to Yahoo Blueprint server, to your own web server --
Ryan Hunter
President
Apax Software Development