Marc-Andre,
If you have your own membership, you don't need standalone application.
Cute Live Support was built with the idea of extensibility in mind. Developers can easily integrate Cute Live Support with any membership database (e.g. portal or forums database). So users can chat with their existing screen names and profiles. No need to recreate everything you already have in place.
To help you quickly use the Cute Live Support in your ASP.NET applications, CuteSoft team has finished the integrations for Cute Live Support standalone, DotNetNuke, Community Server, Snitz Forum(ASP), Rainbow Portal, IbuySpy and Community Starter Kit.
If your portal is not based on the above projects, Cute Live Support easy integration feature offer you an interface to allow users auto-login chat room without entering username and password again once they've logged in your portal or forum.
asp.net Chat http://cutesoft.net/ASP.NET+Chat/default.aspx
Web Messenger: http://cutesoft.net/Web-Messenger/default.aspx
asp.net wysiwyg editor: http://cutesoft.net/ASP.NET+WYSIWYG+Editor/default.aspx
asp wysiwyg html editor: http://cutesoft.net/ASP
asp.net Image Gallery: http://cutesoft.net/ASP.NET+Image+Gallery/default.aspx
Live Support: http://cutesoft.net/live-support/default.aspx