People tend to think that Smalltalk is not widely used as it is not in the (stupid) TIOBE index. But Smalltalk is not only a language but a fully dynamic object system (the language is just built in using objects and messages and fully adoptable which makes it hard to compare to regular programming languages). Compared to any other it is also the most pure object oriented systems.
Mostly other languages started to be "object oriented" for fashion reason without following good OO practice. There is also a very simple reason why Smalltalk is not highly ranked in TIOBE index. You do not need a webbrowser or compiler manual. You can concentrate on the problem solving and lively development in the Smalltalk system instead of googling for keywords, syntax and API's.
Nonetheless there are so many projects and applications that are built in Smalltalk - unfortunately they are not that visible in the first place even when some of them influence us daily like financial applications, container management, railway planning and ERP systems.
I was surprised today to see that someone started a #thingsPeopleBuiltWithSmalltalk campaign on Twitter. Nice initiative!
So if you know something built in Smalltalk then just twitter it:
Lets make 2015 the "There is no excuse not to know about Smalltalk" year ;)