With OpenACS you'll find a web development framework suitable for anything you might want to build atop of it now and in the future, plus a set of packages and abstractions such as subsites, that will enhance your website now and/or in the future. About CMS, there's ETP for simple things, and BCMS for more professional things (not sure about the state of this one now, you might ask openly).
Have a look here:
https://openacs.org/tcltk05/
Plus if you find yourself with time to maintain / contribute a CMS, then even more welcomed.