This site is built on top of the Concursive ConcourseConnect software. It is extremely powerful and includes just about everything one could want for a community/directory/social network.
So what can you do here? After registering, you can not can you have your own blog, forums, wiki and document store, but you can start your own group for a special purpose. I've created one for CP/M and one for TRS-80, but I know there are lots of other old technologies that deserve their own groups.
Some that come to mind are Digital Equipment Coprporation PDP-11 and Vax systems, old Sun hardware and operating system, old UNIX systems, Apple, Commodore, Atari, and who knows what else.
Feel free to register and start a conversation about something that interests you. I know my own interests span systems across the spectrum of mainframes, minis, and micros, operating systems, programming languages and old application software.
Groups have blogs, forums, wikis, document stores, and private messaging, among others. There's lots to play with. Come and play!