ADRIFT has come a long way in the last few releases and is very close to being ready for a full release, but there are a few reasons why i would have to say "not quite yet".
If we ignore the enhancement requests that add new features and all the niggly little bugs, then we are still left with a few obvious holes in the basic functionality that still scream "Beta".
1/ The Hint system is not implimented in the runner.
2/ The Conversation tab of Actions is completely blank, and if you open an existing conversation action you get the message "TODO - Function Load Conversation Actions - Please tell Campbell what you were doing" (Bug 193
3/ "Export Module" writes the entire file instead of a module that you can use as a library. (Bug 115
4/ Clicking the "Create new" button in an expression for a restriction or action produces the message box "TODO: Expression Builder" (Bug 18323
5/ The expression system needs a complete overhaul (Bug 18325
, Bug 18326
, Bug 18327
, Bug 10048
The reason i think this is important is that it changes the API. Any game which uses expressions as they are now will simply not work in future versions of ADRIFT which fix these problems.