Here is a guide with the best free online courses to learn Haskell for both beginners and experienced programmers.

Here are the best free online courses to learn OCaml, a general-purpose, statically-typed programming language that is widely used in academia and research institutions.

TL;DR Duolingo reported Q4 2025 revenue of $282.9 million (+35% YoY), closing its first billion-dollar year, breaking estimates again. The stock dropped 22.5% anyway. Again. The company plans to slow down monetization to grow to 100 million DAUs until 2028, by focusing on teaching quality, giving more to free users, and growing non-language courses. Duolingo’s Q4 2025 results confirmed something we highlighted in its 2025 review: growth is slowing. The company crossed a billion dollars in r

From course ratings to pricing, let’s have a look at some of the discernible trends of Udemy’s catalog.