PUBLIC MARKS from amyrussell with tag json

In the rush to develop entirely new Web 2.0 systems based on Ajax, it is often easy to lose sight of how it can be used to improve the so-called "legacy" enterprise systems. Over at the Ext JS blog, there's a post about German developer who put together a reporting/BI application to front-end RPG code running on an AS400.

Everyone wants the Web 2.0. But how to get there, especially if you have a dowdy old Web 1.0 application? Will I have to spend the annual GDP of a smallish Central American nation on the rewrite? There are three general approaches that evolved over the last year:

I'm sure not everyone is developing Ajax-based front end sites and applications. There must be someone who is developing XML, JSON and JSONP web services, right? So, if you are going to offer it as a commercial service, and even if you aren't, you still want to be able to control and measure access to it. Something like those Google and Yahoo service API keys, right? I'm sure we've all worked with MD5 and SHA-1 enough to have some ideas about how that would be done, but it helps to have an example to follow.