Can anyone explain what's so special about it. Are the rumors true that it was made
by Martians?

Ah, I like that description..."special"...''smiling''.

EnfinSmalltalk was written in C, and it was a set of wrappers that parsed text that conformed to a subset of the Smalltalk grammar into corresponding calls on underlying libraries. There were no bytecodes and minimal reflection. So it was, all in all, a macro processor on steroids.

Actually the above statement is largely false.  EnfinSmalltalk was written in C and and for the first 5-7 months of development was somewhat as described as above (but this code was never released to customers).  By the end of the first year of development (1988) EnfinSmalltalk did indeed run using bytecodes and had the core of reflection.  In the second year of development performance enhancements including special handling of floating point arithmetic were added.  Also during this time the core classes including collections, control flow methods and a persistent store were added.  EnfinSmalltalk was developed by an extremely small set of engineers.  The core code was developed by two engineers with help from a third in approximately one and a half years.  The core was enhanced and extended later, but the original system had most of the hallmarks of a full Smalltalk system completed within the first two years of development.

Enfin was bought by Easel (in either 1990 or 1991), and they were naive enough to not really understand why these attributes mattered. Easel was thus apparently surprised to discover that Enfin was not widely accepted as a full-fledged member of the Smalltalk community. Easel brought in several very strong technical contributors who attempted to sort things out, but was ultimately unsuccessful.

Enfin was sold to Cincom/Vmark, who apparently has also now acquired DarkPlace (yes? I think I read this a while ago).

While Easel owned Enfin, they attempted to layer some interesting tools on top of it ... I think one was called ObjectStudio. Again, unfortunately, the underlying platform could not support the paradigm and the whole concept seems to have disappeared. Perhaps, if its out there, someone can rematerialize it here.

-- TomStambaugh

Enfin was renamed to ObjectStudio, it is not a tool on top of Enfin, more like a bunch of their tools bundled together.

''I suspect this is what ObjectStudio is today. When it was announced (I believe it was late 1993 or early 1994) it was a Forte-like code generation tool on top of Enfin. -- TomStambaugh''

ObjectStudio is actually a full-fledged Smalltalk with real meta-classes, bytecodes and everything.  There are still quite a few methods that are implemented as C primitives, but these are becoming fewer as it is maturing.  

There are tools out there for it.  In fact the SUnit has been ported, and there is a project to port the RefactoringBrowser.  Pieces of that are done, but it has not been completed as far as I know.  ObjectStudio is still used pretty heavily in Europe, but I am not so sure about in the US.

The current version is ObjectStudio 6.2 and you can get a non-commercial version from the Cincom website.

For more information:
http://ostudio.swiki.net/  ''(link not responding)''

''Anybody know the relationship, if any, between ObjectStudio and VisualWorks (which Cincom know owns)? -- TomStambaugh''