It's tagline is "The Smalltalk for those who can type".
However it doesn't look very lively, and you'd be pretty lonely. I don't know any projects using GNU ST. Squeak, and now Pharo, are really the only implementations with momentum right now.
And as far as the typing thing... I am a die-hard Emacs user, and I still enjoy Pharo. This is because programming in Smalltalk is not so much about writing and editing code as it is working with objects. And, frankly, Smalltalk's way of working with objects (and remember: classes and their methods are just objects) is much more powerful than the average editor's way of working with source code.
GNU Smalltalk's actually decently lively, in my opinion. Its lack of updates has a lot more to do with the core being stable than anything else.
The two problems I have with it are simply that it's far slower than Pharo or Squeak, and that using the GPL for a Smalltalk makes me extremely nervous, since the concept of a derivative work gets really dicey when any half-decent Smalltalk app is going to end up throwing new methods into the base library.
The developers at ObjectFusion (http://www.objectfusion.fr/) appear to do much of their development in GNU Smalltalk. That's: Iliad web framework, Odyssey CMS, and possibly the upcoming Smalltalk Hub (the equivalent of GitHub, and an anticipated replacement for SqueakSource).
Unless I'm badly mistaken, SmalltalkHub is now developed on, and for, Pharo, not GNU Smalltalk. I have no insight into the reason for that change, however.
(I'm basing this on the code for SmalltalkHub, which at least used to be available on SmalltalkHub, and which had Pharoisms in the code base. It's entirely possible they simply moved those pieces over to GNU Smalltalk, though.)
http://smalltalk.gnu.org/
It's tagline is "The Smalltalk for those who can type".
However it doesn't look very lively, and you'd be pretty lonely. I don't know any projects using GNU ST. Squeak, and now Pharo, are really the only implementations with momentum right now.
And as far as the typing thing... I am a die-hard Emacs user, and I still enjoy Pharo. This is because programming in Smalltalk is not so much about writing and editing code as it is working with objects. And, frankly, Smalltalk's way of working with objects (and remember: classes and their methods are just objects) is much more powerful than the average editor's way of working with source code.