Duolingo ES from EN versions:

It's too difficult to identify all versions of this huge course!

Tree Versions:
v0: 2011-11-30, ? (beta)
2012-06-19, 61 Skills = Different Lessons)
2015-06-20, 113  "
2018-06-25, 159  "
2020-08-01, 178  "
2020-10-10, 193  "
2020-12-26, 204  "
2021-12-29, 214  "
2021-03-18, 229  "
2021-03-26, 243  "
2021-09-16, 268  "

Path Versions, all CEFR:
2022-08-10, 211 units (551 Different Lessons: 264 Skills, 287 Stories) (CEFR B2)
2022-08-11, 212 units (586 Different Lessons: 269 Skills, 317 Stories) (CEFR B2)
2022-09-10, 207 units (549 Different Lessons: 262 Skills, 287 Stories) (CEFR B2)
2022-11-11, 220 units (563 Different Lessons: 276 Skills, 287 Stories) (CEFR B2)
2023-03-10, 216 units (585 Different Lessons: 268 Skills, 317 Stories) (CEFR B2)
2023-03-12, 230 units (631 Different Lessons: 284 Skills, 347 Stories) (CEFR B2)
2023-08-13, 264 units (731 Different Lessons: 324 Skills, 407 Stories) (CEFR B2)
2023-09-20, 179 units (702 Different Lessons: 252 Skills, 346 Stories, 104 Radios) (CEFR B2)
2023-09-21, 205 units (779 Different Lessons: 286 Skills, 406 Stories, 87 Radios) (CEFR B2)
2024-03-20, 327 units (823 Different Lessons: 323 Skills, 396 Stories, 104 Radios) (CEFR B2)


android_51_grammar_lesson_es_en_pres_1	
android_55_grammar_lesson_es_en_pres_1	
gencon_generated_at_grading_es_en_a1_v1	
gencon_generated_at_grading_es_en_a1_v2	
gencon_generated_at_grading_es_en_a1_v3	
grammar_skills_es_en	
grammar_skills_es_en_b1	
learning_17q3_tree_es_en_v1	
learning_quiz_launch_es_en	
me_add_es_en_b1_3	
path_shorter_grammar_practice_es_en_fr	
ps_sg_grammar_practice_es_en_fr	
slab_android_hark_es_en	
slab_ios_lss_es_en	
stories_es_en_b2	
tree_es_en_a1_0_new	
tree_es_en_b2_1_new_launch	
tree_es_en_b2_2_existing	
tree_es_en_b2_2_new	
tree_es_en_b2_3_b2_4_existing	
tree_es_en_b2_3_b2_4_new	
tree_es_en_shorten_content	
tree_es_en_v7_experiment	
tree_es_en_v8_experiment	
tree_es_en_v12_experiment	
tree_es_en_v13_experiment	
tree_es_en_v14_experiment	
tree_es_en_v15_experiment	
tree_es_en_v16_experiment	
tree_es_en_v17_experiment	
tree_es_en_v18_experiment	
tree_es_en_v19_experiment	
tree_es_en_v20_experiment	
tree_es_en_v21_experiment	
tree_es_en_v22_experiment	
tree_es_en_v23_experiment	
tree_es_en_v24_experiment	
tree_es_en_v25_experiment	
tree_es_en_v26_experiment	
tree_es_en_v27_experiment	
tree_es_en_v29_experiment	
tree_es_en_v30_experiment	
tree_es_en_30_experiment	
tree_es_en_v31_experiment	
tree_es_en_v32_experiment	
tree_es_en_v33_experiment	
tree_es_en_v34_experiment	
tree_es_en_v35_experiment	
tree_es_en_v36_experiment	
tree_es_en_v37_experiment	
tree_es_en_v38_experiment	

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.