Two programming languages, interesting for different reasons:

• The ABC programming language, designed for teaching programming (just as BASIC and Pascal were). It served as inspiration for Python (the colons and whitespace indentation are familiar). It feels sort of halfway between Logo and Python, and is interesting as another datapoint, and as historical background for Pythonistas.
• The D programming language, which seems to have been designed by taking C++, throwing out the worst cruft, adding in some from Java, and letting it simmer a little. It's interesting because it could lead the way to a compromise in the C++/C#/Java wars.