has put all the old International Critical Commentaries (ICC) online. These were written between 1870 and 1924, so are almost all over a century old. But to use an expression from software development, "that's a feature – not a bug."
The authors of these books – most of them British – got an education in Ancient Greek the likes of which is virtually unavailable today. They all started taking Greek (and Latin) in junior high school, and carried on through high school and university. The depth and breadth of their grasp of the language is breathtaking. Put that together with a passion for Scripture, and it is a powerful combination.

Serious students of NT Greek still refer to ICC commentaries today. They are all pretty technical — but if you are having problems with the Greek in a particular verse, or if you want to research how Luke's writing style differed from that of Matthew or Mark, you may well find some help in an ICC commentary.