Change appearence of page dynamically like twitter or tumblr

I'm trying to find tutorials or code to allow users to customise their page, just like twitter ,wordpress and tumblr do.

Could someone tell me what technology their using?

i'm a .net developer, but maybe t开发者_开发问答hey're using jquery?

Any help would be great.

Thanks

You can use javascript to change style sheets and the DOM

Question is a bit broad. To change the page you simply need to manipulate the DOM or change the CSS associated with the page's elements. This can be done any number of ways. E.g. you could write out a new CSS class dynamically, you could add new elements to the DOM itself or you could modify the existing attributes of the page. e.g. to set the background of the page you can do something like:

(assuming JQuery) $("body").css('background-image','url(path/to/image)');

Hope that helps,

-fs