Robot Framework claims to be:
a generic test automation framework for acceptance testing and acceptance test-driven development (ATDD). It has easy-to-use tabular test data syntax and it utilizes the keyword-driven testing approach.
My first impression is that there will be challenges in maintaining tests that combine natural-language text files with real code (as in Fit, Fitnesse) comparing to tests written purely in code. However, that's my only first impression.
Are tests written in Robot Framework easy to maintain? Why yes? Why not?