[MaPi_]

What do you mean? The webchat client is linked right there in the second paragraph, doesn't require you to install anything and let's you connect and list channels as a guest without registering. It took me like 30 seconds to find out that there is indeed an astronomy channel.

[dotancohen]

It was not clear to me that was a web browser interface, because it listed system requirements - none of which were an actual web browser.

[zmatt]

Uhh, I'm not seeing any system requirements, am I blind? It just warns against using the /list command if you have a very slow internet connection since it produces rather voluminous output. If you scroll down a bit further they also link to a third-party website that has a searchable index of all publicly visible channels.