ACME has turned out to be a good deal more reliable than any other products of the same name.
It's a C# component which uses Windows Presentation Foundation or #WPF. This makes it Windows Desktop only.
But the reason we wrote it is because there is a *real* drought of free, reusable .NET chemical components.
Also #CML, which ACME uses, allows much more sophisticated molecule handling. For instance, you can nest molecules in a parent-child structure.