Share 'Moving from List Serv software to social networking platform?'

We have a moderately successful technical question list serve that's pretty old running on ugly old Lyris software. It seems to be a good basis to build a community to give them the ability to post in HTML, etc. We looked at Andy Steggles' software to do this and it was quite impressive. Has anyone else moved an old list serve to social network? Did you use something proprietary or an open plat...