07-12-2011 07:55 AM
I've personally never attempted to do this but I imagine it may be possible. I wouldn't recommend it however as you wouldn't be able to debug.
07-18-2011 02:44 PM
While technically you can develop your plugin or customer control by just copying the necessary libraries to your development box, you cannot deploy your solution to a machine that does not have ACT! installed.
I.E. For Development purposes - yes you do not need ACT! installed (though as Matt points out debugging becomes more difficult).
For deploying your plugins or customer control you need an ACT! install (not just runtime copied of the ACT! Framework).