As of version 126.96.36.199, mojoPortal now includes the MS AJAX framework and you can leverage it in your development of custom features. The ScriptManager control has been added to the layout.master file of all skins. For example if you want to setup an asynchronous postback for a button, you can do it like this:
ScriptController is a reference to the ScriptManager control in layout.master and this reference is built in to the mojoBasePage and the SiteModuleControl which are the 2 main base classes used in implementing custom features.
You can also use the UpdatePanel or any other of the System.Web.Extensions provided features.
By default WebParts drag and drop feature only works in Internet Explorer but with Microsoft.Web.Preview.dll it can work in Firefox and Safari.