Microsoft has announced a pre-release version of the Skype client that runs in any modern web browser, allowing users to make audio and video calls from any PC or Mac. Soon, you'll be able to sign-in at skype.com to get started, but for now the release is available only to a very limited audience.

Skype for Web (Beta)—as this initial release is called—won't replace the desktop or modern Skype client on your PC. But it could be handy anytime you're using someone else's PC, say in an Internet café or hotel.

Skype for Web (Beta) works with Internet Explorer 10+, and the latest versions of Chrome and Firefox on Windows-based PCs, and with Safari on a Mac, Microsoft says. For now it's available only to a small number of existing and new users, and will gradually roll out worldwide "in the coming months." It's not clear how you can get the release any earlier, Microsoft just says to look out for an invite.

I've not experienced the web client yet myself, but Microsoft says the web client will support instant messaging, voice calls and video calls.

The firm does say, however, that you will need to install a small plug-in to start a voice or video conversation. But it's not totally clear if that's a requirement for Internet Explorer only, or whether that impacts other browsers too. (The post notes that the IE team is "starting to implement the technology to make Real-Time Communications (RTC) on the web a reality," so a plug-in-less future is coming at some point.)