As stated in the overview[1], the purpose of The Grid is "to provide a platform for collaborative creation and communication. Connected clients can chat, edit a wiki, send auto-opening web links and references to files, upload to a shared ramdisk, and access a read-only version of the root filesystem used by the grid servers, with a library of installed software".
The Grid aligns very well with Plan 9 ecosystem and is very easy to get up and running, basically all you need is a gridup[2] script. You run it once, it spawns a nested rio with all the grid-related stuff inside: chat, editor, mothra and page. Every time someone wants to send a link (or a file) they just plumb it and everyone can instantly see it in their grid rio. MAGIC.
And yes, the Grid is very much active.
For those willing to maybe just lurk around without having to go through 9front installation process there are alternatives for chat clients: 9gc[3] that compiles and runs under any Unix-like OS (including in termux on android), and another one as a web page[4].
