Comparing YUI and Ext JS [closed]

Question

I've been using Ext JS as my rich-widget toolkit for a while, but I'm thinking of moving to YUI, partly because of the less restrictive license.

The component-oriented model used in YUI seems quite similar to the one that I've enjoyed so much in Ext JS, but I'm interested in how deep those similarities are. So I'm interested in feedback from people who've used both Ext JS and YUI. What is the same, and what is different? What do I lose by moving to YUI, and what do I gain?

Answer 1

I think both libraries actually address different needs.

YUI is designed addresses the needs of Yahoo inc. It is very good at building public facing applications where things like graceful degradation, clean markup and accessibility is important.

ExtJS is a very good and well designed full RIA framework that is very firmly targeted at building line of business applications. Features such as a really powerful grid component, strong layout and good professional look and feel.

I've used both quite considerably, although only up to YUI 2.7.0 and have built several full RIA using the frameworks.

Moving an existing application from one to another would be quite differcult as although they share a common ancestor (ExtJS was once YUIext) the frameworks are quite different now.

Answer 2

One major difference is that YUI is distributed under the extremely permissive BSD license whereas ExtJS is distributed under a very viral interpretation of the GPL. For instance, with Sencha's interpretation of the GPL, if you write a SOAP or REST interface specifically to talk to an ExtJS front end then your server code must be GPL and you must provide access to the source since you have "distributed" it by granting access over the web. Sencha does provide a commercial license for their code but if you read their docs carefully you will see that they do not allow you to convert code you wrote against GPL Sencha to another license when you switch to the commercial version. (http://www.sencha.com/legal/license-overview)

In short, if your code needs to integrate with proprietary business logic or commercially licensed systems then you must develop using the commercial version of Sencha from the outset.

Answer 3

For me the difference is that YUI is very lightweight and flexible, whereas ExtJS is heavier, with a bigger footprint and more rigid in the way you use it. YUI is great if you know what you're doing in Javascript and want to extend your power; ExtJS is good if you want a UI abstraction layer that you don't have to mess with much ... but if you do want to make it do things it wasn't designed to do, it can be a real chore.