Besides releasing the OpenXenManager tool the XenseMaking project also provides the XenWebManager tool.
XenWebManager is a web-based open source clone of Citrix Xencenter. With XenWebManager you only need a browser for manage your server and virtual machines. With full packages you only need have installed python (2.4+). For console access you only need a browser with java plug-in or a browser with html5 websockets.
To test the functionality, the XensMaking project hosts an appliance which can be downloaded to test XenWebManager, the root password for that appliance is xenwebmanager.