I was reading through an answer to a question about an IDE for Go that triggered this question.
I was trying to think of a language that 'required' an IDE, but could not come up with one.
Many of the "graphical languages" more or less require an IDE. They aren't particularly popular at the moment, but the general idea is a "language" where you create programs by drawing some sort of diagram. Depending on the intended market, you frequently see something with a flavor or UML or ERD or even flowcharting, depending on the intended market, age of the tool, and level of obfuscation versatility and ease of use the inventor/vendor desires.
While most of these allow you to store the data in some sort of more or less textual format, they consider the diagram (of whatever sort) to be the language, and anything else is only a way of storing/recreating the diagram.