K-12 education standards in the U.S. require all students to read complex texts across many subject areas. The "Language Muse™ Activity Palette" is a web-based language-instruction application that uses NLP algorithms and lexical resources to automatically generate language activities and support English language learners' content comprehension and language skills development. The system's online platform for activity generation, scoring, and feedback is scalable for MOOCs, as well as for other online learning settings. [This paper was published in: "Proceeding L@S '17 Proceedings of the Fourth (2017) ACM Conference on Learning @ Scale" Cambridge, Massachusetts, p213-215. ACM New York, NY. 2017.]