just stands for the meta-category on linked wiki which regroups all categories whose names begin with the letter I.
Maybe you were searching for Category: Programming Languages
], which is the meta-category on same wiki which regroups all categories concerning individual programming languages.
A final note though: the site you refer to regroup concepts about generic algorithms or requirements, with implemented examples in as much distinct languages as possible. Thus, it is not the best source if you are interested in the knowledge of a specific language.
It remains unclear which type of information you are searching for.