Just hours after it launched final versions of almost all of its Windows Live-branded services and software, Microsoft also debuted a beta of Windows Live Calendar, its iCal-compliant, next-generation online scheduler.

The replacement for MSN Calendar -- the current companion to Microsoft's Web e-mail service -- the beta of Windows Live Calendar features multiple calendars, shared calendars, e-mail and text message alerts tied to appointments, and the ability to subscribe to a calendar's contents via Real Simple Syndication.

Built using Asynchronous JavaScript and XML (AJAX), the application boasts some desktop-style navigation -- including drag and drop, single click to add an appointment, and scrolling through dates using a mouse wheel, said Denise Ho, lead program manager for the product.

Shared calendars can be opened to others through a sophisticated rights management process, added Ho. "Share as much or as little of your calendar with free/busy, read-only or read/write permissions," she said in a posting to the team's blog. "[Or] send friends a view-only secret link to your calendar so they don't need to sign in with a Windows Live ID." The options also include a new co-owner role that lets another user control the calendar but prevents them from moving or deleting it.

Although Windows Live Calendar supports the iCal standard -- which lets users manually merge it with content on other iCal-based calendars, such as Google Calendar -- the beta lacks synchronization.

While Windows Live Calendar is in beta, existing MSN Calendar content will remain untouched, said Ho.

Users can opt for the beta here; a Windows Live ID is required.