Duolingo HT from EN versions:

Trees:
v0: 2017-01-27  ? (Beta)
v0: 2022-01-14, 113 Skills (113 Different Lessons) (Beta)
v1: 2022-02-22, 36 Skills (36 Different Lessons)

Paths:
1.0: 2022-09-10, 36 Skills (36 Different Lessons) (23 units)
1.1: 2023-09-10, 36 Skills (36 Different Lessons) (23 units)
2.0: 2024-04-03, 68 Skills (68 Different Lessons) (44 units)
1.2: 2024-05-01, 36 Skills (36 Different Lessons) (41 units)

tree_ht_en_section_2_3
tree_ht_en_v2_new
tree_ht_en_v3_existing

https://liuch.github.io/duolingo_courses_overview/
https://duolingo.fandom.com/wiki/Course_list
https://duolingodata.com/
https://duolingodata.com/oldtable.html
https://ardslot.com/duolingocrowns.html

Edited by Mat!/Ozone, 2024-05-02.