Which is correct: "Grails" or "The Grails"?
Solution 1:
Usually, as other answers note, names of software products and other proper-noun names don't take the.
Yet some, especially plurals, do, like the Netherlands, the Internet, and the Web. (To be honest, I can't think of a software product whose name takes the. Nonetheless,) I think it simply depends on what the common use is for any given proper noun: try to find Grails and the Grails (and The Grails, I suppose) in use.
Solution 2:
"Grails has integration with jUnit"
"Grails" is a proper name. So the article is dropped.
Example:
"George has a lollipop."
NOT
"The George has a lollipop."
Solution 3:
We usually do not use the in front of software names. Nobody says the Windows, the Perl or the Python. However, in a sentence like
The Windows computer is still working,
the article really refers to the computer.