This is the first in an occasional series of my interpretation of 3 acronyms.

XHR: XMLHttpRequest, javascript and other scripting languages API to transfer XML data from a web server to a client using HTTP. An important part of AJAX. Without this Google maps would not have happened.

Reverse AJAX: Give me strength. For a start ‘Reverse’ isn’t an acronym. What this stuff does is, whereas AJAX goes to the server to get data to update the browser, with Reverse Ajax the communication is instigated from the server by pushing data to the client. Normal AJAX does a pull thing. So how does the server make communication with the browser. Not easily as browsers only really listen for answers to questions they have asked. And of course there is the problem with firewalls. The first way is for the browser to poll often, like say every few seconds. The second way is for the server to load the data to the browser slowly just to keep the channel open. Thirdly, there is the piggy-back way, where as soon as the browser talks to the server then the server pounces on it providing the answer to the browsers question plus all the updates that the poor server has been itching to download since the last browser invoked question. Clear as mud?

JSON: Sort of XML Lite. Used a lot in Javascript and if used in AJAX would actually have the acronym AJAJ. Can also be used to create data types and structures for the following languages: Coldfusion, Java, Perl, Python, Ruby, PHP and Smalltalk amongst others.

Quote of the day

‘The reverse side also has a reverse side’ Japanese Proverb